7
Hindawi Publishing Corporation ISRN Mathematical Analysis Volume 2013, Article ID 382312, 6 pages http://dx.doi.org/10.1155/2013/382312 Research Article A Subclass of Harmonic Univalent Functions Associated with -Analogue of Dziok-Srivastava Operator Huda Aldweby and Maslina Darus School of Mathematical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia Correspondence should be addressed to Maslina Darus; [email protected] Received 26 June 2013; Accepted 1 August 2013 Academic Editors: G. ´ Olafsson and D.-X. Zhou Copyright © 2013 H. Aldweby and M. Darus. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We study a class of complex-valued harmonic univalent functions using a generalized operator involving basic hypergeometric function. Precisely, we give a necessary and sufficient coefficient condition for functions in this class. Distortion bounds, extreme points, and neighborhood of such functions are also considered. 1. Introduction Let U = { ∈ C : || < 1} be the open unit disc, and let denote the class of functions which are complex valued, harmonic, univalent, and sense preserving in U normalized by (0) = (0) − 1 = 0. Each can be expressed as =ℎ+ , where and are analytic in U. We call the analytic part and the coanalytic part of . A necessary and sufficient condition for to be locally univalent and sense preserving in U is that |ℎ ()| > | ()| in U (see [1]). In [2], there is a more comprehensive study on harmonic univalent functions. us, for =ℎ+ , we may write ℎ () = + =2 , () = =1 (0 ≤ 1 < 1) . (1) Note that reduces to , the class of normalized analytic univalent functions, if the coanalytic part of =ℎ+ is identically zero. e study of basic hypergeometric series (also called - hypergeometric series) essentially started in 1748 when Euler considered the infinite product (; ) −1 =∏ =0 (1 − +1 ) −1 . In the literature, we were told that the development of these functions was much slower until, in 1878, Heine converted a simple observation that lim →1 [(1 − )/(1 − )] = which returns the theory of 2 1 basic hypergeometric series to the famous theory of Gauss’s 2 1 hypergeometric series. e importance of basic hypergeometric functions is due to their application in deriving -analogue of well-known functions, such as -analogues of the exponential, gamma, and beta functions. In this paper, we define a class of starlike har- monic functions using basic hypergeometric functions and investigate its properties like coefficient condition, distortion theorem, and extreme points. For complex parameters , , ( = 1, . . . , , =1,...,, C \ {0, −1, −2, . . .}, || < 1), we define the basic hypergeometric function Φ ( 1 ,..., ; 1 ,..., , , ) by Φ ( 1 ..., ; 1 ,..., , , ) = =0 ( 1 , ) ⋅ ⋅ ⋅ ( , ) (, ) ( 1 , ) ⋅ ⋅ ⋅ ( , ) , (2) ( = + 1; , ∈ N 0 = N ∪ {0}; ∈ U) where N denote the set of positive integers and (, ) is the -shiſted factorial defined by (, ) ={ 1, = 0; (1 − ) (1 − ) (1 − 2 ) ⋅ ⋅ ⋅ (1 − −1 ), N. (3)

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Page 1: HudaAldwebyandMaslinaDarus - downloads.hindawi.comdownloads.hindawi.com/archive/2013/382312.pdf · Correspondence should be addressed to Maslina Darus; maslina@ukm.my Received June

Hindawi Publishing CorporationISRNMathematical AnalysisVolume 2013 Article ID 382312 6 pageshttpdxdoiorg1011552013382312

Research ArticleA Subclass of Harmonic Univalent Functions Associated with119902-Analogue of Dziok-Srivastava Operator

Huda Aldweby and Maslina Darus

School of Mathematical Sciences Faculty of Science and Technology Universiti Kebangsaan Malaysia43600 Bangi Selangor Malaysia

Correspondence should be addressed to Maslina Darus maslinaukmmy

Received 26 June 2013 Accepted 1 August 2013

Academic Editors G Olafsson and D-X Zhou

Copyright copy 2013 H Aldweby and M Darus This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

We study a class of complex-valued harmonic univalent functions using a generalized operator involving basic hypergeometricfunction Precisely we give a necessary and sufficient coefficient condition for functions in this class Distortion bounds extremepoints and neighborhood of such functions are also considered

1 Introduction

Let U = 119911 isin C |119911| lt 1 be the open unit disc and let119878119867denote the class of functions which are complex valued

harmonic univalent and sense preserving in U normalizedby 119891(0) = 119891

119911(0) minus 1 = 0 Each 119891 isin 119878

119867can be expressed as

119891 = ℎ + 119892 where ℎ and 119892 are analytic in U We call ℎ theanalytic part and 119892 the coanalytic part of 119891 A necessary andsufficient condition for 119891 to be locally univalent and sensepreserving in U is that |ℎ1015840(119911)| gt |1198921015840(119911)| in U (see [1]) In [2]there is a more comprehensive study on harmonic univalentfunctions Thus for 119891 = ℎ + 119892 isin 119878

119867 we may write

ℎ (119911) = 119911 +

infin

sum

119896=2

119886119896119911

119896 119892 (119911) =

infin

sum

119896=1

119887119896119911

119896(0 le 119887

1lt 1)

(1)

Note that 119878119867reduces to 119878 the class of normalized analytic

univalent functions if the coanalytic part of 119891 = ℎ + 119892 isidentically zero

The study of basic hypergeometric series (also called 119902-hypergeometric series) essentially started in 1748 when Eulerconsidered the infinite product (119902 119902)minus1

infin= prod

infin

119896=0(1 minus 119902

119896+1)

minus1In the literature we were told that the development of thesefunctions was much slower until in 1878 Heine converteda simple observation that lim

119902rarr1[(1 minus 119902

119886)(1 minus 119902)] = 119886

which returns the theory of21206011basic hypergeometric series to

the famous theory of Gaussrsquos21198651hypergeometric series The

importance of basic hypergeometric functions is due to theirapplication in deriving 119902-analogue of well-known functionssuch as 119902-analogues of the exponential gamma and betafunctions In this paper we define a class of starlike har-monic functions using basic hypergeometric functions andinvestigate its properties like coefficient condition distortiontheorem and extreme points

For complex parameters 119886119894 119887119895 119902 (119894 = 1 119903 119895 = 1 119904

119887119895isin C 0 minus1 minus2 |119902| lt 1) we define the basic

hypergeometric function119903Φ119904(1198861 119886

119903 1198871 119887

119904 119902 119911) by

119903Φ119904(1198861 119886119903 1198871 119887

119904 119902 119911)

=

infin

sum

119896=0

(1198861 119902)

119896sdot sdot sdot (119886119903 119902)

119896

(119902 119902)

119896(1198871 119902)

119896sdot sdot sdot (119887119904 119902)

119896

119911

119896

(2)

(119903 = 119904 + 1 119903 119904 isin N0= N cup 0 119911 isin U) where N denote

the set of positive integers and (119886 119902)119896is the 119902-shifted factorial

defined by

(119886 119902)

119896

=

1 119896 = 0

(1 minus 119886) (1 minus 119886119902) (1 minus 119886119902

2) sdot sdot sdot (1 minus 119886119902

119896minus1) 119896 isin N

(3)

2 ISRNMathematical Analysis

We note that

lim119902rarr1

minus

[119903Φ119904(119902

1198861

119902

119886119903

119902

1198871

119902

119887119904

119902 (119902 minus 1)

1+119904minus119903119911)]

=119903119865119904(1198861 119886

119903 1198871 119887

119904 119911)

(4)

where119903119865119904(1198861 119886

119903 1198871 119887

119904 119911) is the well-known general-

ized hypergeometric function By the ratio test one observesthat for |119902| lt 1 and 119903 = 119904 + 1 the series defined in (2)converges absolutely in U so that it represented an analyticfunction in U For more mathematical background of basichypergeometric functions one may refer to [3 4]

The 119902-derivative of a function ℎ(119909) is defined by

119863119902 (ℎ (119909)) =

ℎ (119902119909) minus ℎ (119909)

(119902 minus 1) 119909

119902 = 1 119909 = 0 (5)

For a function ℎ(119911) = 119911119896 we can observe that

119863119902 (ℎ (119911)) = 119863119902

(119911

119896) =

1 minus 119902

119896

1 minus 119902

119911

119896minus1= [119896]119902

119911

119896minus1 (6)

Then lim119902rarr1

119863119902(ℎ(119911)) = lim

119902rarr1[119896]119902119911

119896minus1= 119896119911

119896minus1= ℎ

1015840(119911)

where ℎ1015840(119911) is the ordinary derivative For more properties of119863119902 see [4 5]Corresponding to the function

119903Φ119904(1198861 119886

119903 1198871 119887

119904

119902 119911) consider

119903G119904(1198861 119886

119903 1198871 119887

119904 119902 119911)

= 119911119903Φ119904(1198861 119886

119903 1198871 119887

119904 119902 119911)

= 119911 +

infin

sum

119896=2

(1198861 119902)

119896minus1sdot sdot sdot (119886119903 119902)

119896minus1

(119902 119902)

119896minus1(1198871 119902)

119896minus1sdot sdot sdot (119887119904 119902)

119896minus1

119911

119896

(7)

The authors [6] defined the linear operator 119867119903119904(1198861 119886

119903

1198871 119887

119904 119902)119891 A rarr A by

119867

119903

119904(1198861 119886

119903 1198871 119887

119904 119902) 119891 (119911)

=119903G119904(1198861 119886

119903 1198871 119887

119904 119902 119911) lowast 119891 (119911)

= 119911 +

infin

sum

119896=2

Γ (1198861 119902 119896) 119886

119896119911

119896

(8)

where (lowast) stands for convolution and

Γ (1198861 119902 119896) =

(1198861 119902)

119896minus1sdot sdot sdot (119886119903 119902)

119896minus1

(119902 119902)

119896minus1(1198871 119902)

119896minus1sdot sdot sdot (119887119904 119902)

119896minus1

(9)

To make the notation simple we write

119867

119903

119904[1198861 119902] 119891 (119911) = 119867

119903

119904(1198861 119886

119903 1198871 119887

119904 119902) 119891 (119911) (10)

We define the operator (8) of harmonic function 119891 = ℎ + 119892given by (1) as

119867

119903

119904[1198861 119902] 119891 (119911) = 119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911) (11)

Definition 1 For 0 le 120575 lt 1 let 119878lowast119867(1198861 120575 119902) denote the

subfamily of starlike harmonic functions 119891 isin 119878lowast119867of the form

(1) such that

120597

120597120579

(arg119867119903119904[1198861 119902] 119891) ge 120575 |119911| = 119903 lt 1 (12)

Following [7] a function 119891 is said to be in the class119881119867(1198861 120575 119902) = 119878

lowast

119867(1198861 120575 119902) cap 119881

119867if 119891 of the form (1) satisfies

the condition that

arg (119886119896) = 120579119896

arg (119887119896) = 120599119896 (119896 ge 119899 + 1 119899 isin N) (13)

and if there exists a real number 120588 such that

120579119896+ (119896 minus 1) 120601 equiv 120587 (mod 2120587) 120599

119896+ (119896 minus 1) 120601 equiv 0

(119896 ge 119899 + 1 119899 isin N) (14)

By specializing the parameters of 119867119903119904[1198861 119902]119891 we obtain

different classes of starlike harmonic functions for example

(i) for 119903 = 119904 + 1 1198862= 1198871 119886

119903= 119887119904 119878lowast119867(119902 119902 120575) =

119878119867(120575) [8] is the class of sense-preserving harmonicunivalent functions 119891 which are starlike of order 120575 inU that is 120597120597120579(arg119891(119903119890i120579)) ge 120575

(ii) for 119903 = 119904 + 1 1198862= 1198871 119886

119903= 119887119904 and 119886

1=

119902

119899+1 119902 rarr 1 119878lowast

119867(119902

119899+1 119902 120575) = 119877

119867(119899 120572) [9] is the

class of starlike harmonic univalent functions with(120597120597120579)(arg119863119899119891(119911)) ge 120575 where 119863 is the Ruscheweyhderivative (see [10])

(iii) for 119894 = 1 119903 119895 = 1 119904 119903 = 119904 + 1 119886119894= 119902

120572119894

and 119887119895= 119902

120573119895 119902 rarr 1 119878lowast

119867(1198861 119902 120575) = 119878

lowast

119867(1205721 120575) [11]

is the class of starlike harmonic univalent functionswith (120597120597120579)(arg119867119903

119904[1205721]119891) ge 120575 where 119867119903

119904[1205721] is the

Dziok-Srivastava operator (see [12])

2 Main Results

In our first theorem we introduce a sufficient coefficientbound for harmonic functions in 119878lowast

119867(1198861 120575 119902)

Theorem 2 Let 119891 = ℎ + 119892 be given by (1) If

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896)

le 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

(15)

where 1198861= 1 0 le 120575 lt 1 and Γ(119886

1 119902 119896) is given by (9) then

119891 isin 119878

lowast

119867(1198861 120575 119902)

ISRNMathematical Analysis 3

Proof To prove that 119891 isin 119878lowast119867(1198861 120575 119902) we only need to show

that if (15) holds then the required condition (12) is satisfiedFor (12) we can write

120597

120597120579

(arg119867119903119904[1198861 119902] 119891 (119911))

= R

119911119863119902(119867

119903

119904[1198861 119902] ℎ (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus

119911119863119902(119867

119903

119904[1198861 119902] 119892 (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

= R119860 (119911)

119861 (119911)

(16)

Using the fact that R(119908) ge 120575 if and only if |1 minus 120575 + 119908| ge|1 + 120575 minus 119908| it suffices to show that

|119860 (119911) + (1 minus 120575) 119861 (119911)| minus |119860 (119911) minus (1 + 120575) 119861 (119911)| ge 0 (17)

Substituting for 119860(119911) and 119861(119911) in (15) yields

|119860 (119911) + (1 minus 120575) 119861 (119911)| minus |119860 (119911) minus (1 + 120575) 119861 (119911)|

ge (2 minus 120575) |119911| minus

infin

sum

119896=2

([119896]119902+ 1 minus 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

|119911|

119896

minus

infin

sum

119896=1

([119896]119902minus 1 + 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

|119911|

119896

minus 120575 |119911| minus

infin

sum

119896=2

([119896]119902minus 1 minus 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

|119911|

119896

minus

infin

sum

119896=1

([119896]119902+ 1 + 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

|119911|

119896

ge 2 (1 minus 120575) |119911| 1 minus

infin

sum

119896=2

[119896]119902minus 120575

1 minus 120575

Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

minus

infin

sum

119896=1

[119896]119902+ 120575

1 minus 120575

Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

= 2 (1 minus 120575) |119911| 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

minus [

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

)]

times Γ (1198861 119902 119896)

(18)

The last expression is nonnegative by (15) and so 119891 isin

119878

lowast

119867(1198861 120575 119902)

Nowwe obtain the necessary and sufficient conditions for119891 = ℎ + g given by (14)

Theorem 3 Let 119891 = ℎ + 119892 be given by (11) Then 119891 isin

119881

119867(1198861 120575 119902) if and only if

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896)

le 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

(19)

where 1198861= 1 0 le 120575 lt 1 and Γ(119886

1 119902 119896) is given by (9)

Proof Since 119881

119867(1198861 120575 119902) sub 119878

lowast

119867(1198861 120575 119902) we only to

prove the only if part of the theorem So that for func-tions 119891 isin 119881

119867(1198861 120575 119902) we notice that the condition

(120597120597120579)(arg119867119903119904[1198861 119902]119891(119911)) ge 120575 is equivalent to

120597

120597120579

(arg119867119903119904[1198861 119902] 119891 (119911)) minus 120575

= R119911119863119902(119867

119903

119904[1198861 119902] ℎ (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus

119911119863119902(119867

119903

119904[1198861 119902] 119892 (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus120575 ge 0

(20)

That is

R[

[

(1 minus 120575) 119911 + sum

infin

119896=2([119896]119902

minus 120575) Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

119911

119896minus sum

infin

119896=1([119896]119902

+ 120575) Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

119911

119896

119911 + sum

infin

119896=2Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

119911

119896+ sum

infin

119896=1Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

119911

119896

]

]

ge 0 (21)

4 ISRNMathematical Analysis

The previous condition must hold for all values of 119911 in UUpon choosing 120601 according to (14) we must have

(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

minus

sum

infin

119896=2(([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

ge 0

(22)

If condition (19) does not hold then the numerator in (22)is negative for 119903 sufficiently close to 1 Hence there exist1199110= 1199030in (01) for which the quotient of (22) is negativeThis

contradicts the fact that 119891 isin 119881119867(1198861 120575 119902) and this completes

the proof

The following theorem gives the distortion bounds forfunctions in119881

119867(1198861 120575 119902)which yield a covering result for this

class

Theorem 4 If 119891 isin 119881119867(1198861 120575 119902) then

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

+

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

ge (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

minus

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

(23)

where

Γ (1198861 119902 2) =

(1 minus 1198861) sdot sdot sdot (1 minus 119886

119903)

(1 minus 119902) (1 minus 1198871) sdot sdot sdot (1 minus 119887

119904)

[2]119902= (119902 + 1)

(24)

Proof Wewill only prove the right hand inequalityThe prooffor the left hand inequality is similar

let 119891 isin 119881119867(1198861 120575 119902) Taking the absolute value of 119891 we

obtain

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

119896

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

2

(25)

That is

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ([2]119902

minus 120575)

times

infin

sum

119896=2

(

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

)

times Γ (1198861 119902 2) 119903

2

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ((119902 + 1) minus 120575)

times [1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

] 119903

2

= (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1

Γ (1198861 119902 2)

times [

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

2

(26)

Corollary 5 Let 119891 be of the form (1) so that 119891 isin 119881119867(1198861 120575 119902)

Then

119908 |119908| lt

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) minus 120575) Γ (1198861 119902 2)

minus

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) + 120575) Γ (1198861 119902 2)

1003816100381610038161003816

1198871

1003816100381610038161003816

sub 119891 (U)

(27)

Next one determines the extreme points of closed convex hullof 119881119867(1198861 120575 119902) denoted by clco119881

119867(1198861 120575 119902)

Theorem 6 Set

120582119896=

1 minus 120575

([119896]119902minus 120575) Γ (119886

1 119902 119896)

120583119896=

1 minus 120575

([119896]119902+ 120575) Γ (119886

1 119902 119896)

(28)

For 1198871fixed the extreme points for clco119881

119867(1198861 120575 119902) are

119911 + 120582119896119909119911

119896+ 1198871119911 cup 119911 + 119887

1119911 + 120583119896119909119911

119896 (29)

where 119896 ge 2 and |119909| = 1 minus |1198871|

Proof Any function 119891 isin clco119881119867(1198861 120575 119902) may be expressed

as

119891 (119911) = 119911 +

infin

sum

119896=2

1003816100381610038161003816

119886119896

1003816100381610038161003816

119890

119894120572119896

119911

119896+ 1198871119911 +

infin

sum

119896=2

1003816100381610038161003816

119887119896

1003816100381610038161003816

119890

119894120573119896

119911

119896 (30)

ISRNMathematical Analysis 5

where the coefficients satisfy the inequality (15) Set ℎ1(119911) =

119911 1198921(119911) = 119887

1119911 ℎ119896(119911) = 119911 + 120582

119896119890

119894120572119896

119911

119896 and 119892119896(119911) = 119887

1(119911) +

119890

119894120573119896

119911

119896 for 119896 = 2 3 Writing 119883119896= |119886119896|120582119896 119884119896= |119887119896|120583119896

119896 = 2 3 and1198831= 1minussum

infin

119896=2119883119896 1198841= 1minussum

infin

119896=2119884119896 we have

119891 (119911) =

infin

sum

119896=1

(119883119896ℎ119896 (119911) + 119884119896

119892119896 (119911)) (31)

In particular set

1198911 (119911) = 119911 + 1198871

119911 119891119896 (119911) = 119911 + 120582119896

119909119911

119896+ 1198871119911 + 120583119896119910119911

119896

(119896 ge 2 |119909| +

1003816100381610038161003816

119910

1003816100381610038161003816

= 1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(32)

Therefore the extreme points of clco119881119867(1198861 120575 119902) are

contained in 119891119896(119911) To see that 119891

1is not an extreme point

note that1198911may be written as a convex linear combination of

functions in clco119881119867(1198861 120575 119902) as follows

1198911 (119911) =

1

2

1198911 (119911) + 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

+

1

2

1198911 (119911) minus 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

(33)

If both |119909| = 0 and |119910| = 0 we will show that it can also beexpressed as a convex linear combination of functions inclco119881

119867(1198861 120575 119902) Without loss of generality assume that |119909| ge

|119910| Choose 120598 gt 0 small enough so that 120598 lt |119909||119910| Set119860 = 1 + 120598 and 119861 = 1 minus |120598119909119910| We then see that both

1199051 (119911) = 119911 + 120582119896

119860119909119911

119896+ 1198871119911 + 120583119896119910119861119911

119896

1199052 (119911) = 119911 + 120582119896 (

2 minus 119860) 119909119911

119896+ 1198871119911 + 120583119896119910 (2 minus 119861) 119911

119896

(34)

are in clco119881119867(1198861 120575 119902) and note that

119891119899 (119911) =

1

2

1199051 (119911) + 1199052 (

119911) (35)

The extremal coefficient bound shows that the functions ofthe form (29) are extreme points for clco119881

119867(1198861 120575 119902) and so

the proof is complete

Following the earlier works in [2 13] we refer to the 120574-neighborhood of the functions 119891 defined by (1) to be the setof functions 119865 for which

119873120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

119896 (

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

) +

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(36)

We define the 119902-120574-neighborhood of a function 119891 isin 119878119867as

follows

119873

119902

120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

[119896]119902(

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

)

+

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(37)

In our case let us define the generalized 119902-120574-neighborhood of 119891 to be the set

119873

119902

120574(119891) = 119865

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

]

+ (1 + 120575)

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le (1 minus 120575) 120574

(38)

Theorem 7 Let 119891 be given by (1) If 119891 satisfies the conditions

infin

sum

119896=2

[119896]119902([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

Γ (1198861 119902 119896)

+

infin

sum

1=2

[119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

Γ (1198861 119902 119896) le 1 minus 120575

0 le 120575 lt 1

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(39)

then119873119902120574(119891) sub 119878

lowast

119867(1198861 120575 119902)

Proof Let 119891 satisfy (39) and let

119865 (119911) = 119911 + 1198611119911 +

infin

sum

119896=2

(119860119896119911

119896+ 119861119896119911

119896) (40)

belong to119873119902120574(119891) We have

(1 + 120575)

1003816100381610038161003816

1198611

1003816100381610038161003816

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896

1003816100381610038161003816

]

le (1 + 120575)

1003816100381610038161003816

1198611minus 1198871

1003816100381610038161003816

+ (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

6 ISRNMathematical Analysis

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896minus 119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896minus 119887119896

1003816100381610038161003816

]

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

[2]119902minus 120575

infin

sum

119896=2

Γ (1198861 119902 119896) [[119896]119902

([119896]119902minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ [119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

(119902 + 1) minus 120575

times [(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

] le 1 minus 120575

(41)

Hence

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

119865 isin 119878

lowast

119867(1198861 120575 119902)

(42)

Acknowledgment

The work presented here was partially supported by LRGSTD2011UKMICT0302 and UKM-DLP-2011-050

References

[1] J Clunie and T Sheil-Small ldquoHarmonic univalent functionsrdquoAnnales Academiae Scientiarum Fennicae A vol 9 pp 3ndash251984

[2] Y Avcı and E Złotkiewicz ldquoOn harmonic univalent mappingsrdquoAnnales Universitatis Mariae Curie-Skłodowska A vol 44 pp1ndash7 1990

[3] G Gasper and M Rahman Basic Hypergeometric Series vol 35of Encyclopedia of Mathematics and Its Applications CambridgeUniversity Press Cambridge UK 1990

[4] H Exton q-hypergeometric functions and applications EllisHorwood Series Mathematics and its Applications Ellis Hor-wood Chichester UK 1983

[5] H A Ghany ldquo119902-derivative of basic hypergeometric series withrespect to parametersrdquo International Journal of MathematicalAnalysis vol 3 no 33-36 pp 1617ndash1632 2009

[6] A Mohammed and M Darus ldquoA generalized operator involv-ing the 119902-hypergeometric functionrdquoMatematicki Vesnik vol 65no 4 pp 454ndash465 2013

[7] J M Jahangiri and H Silverman ldquoHarmonic univalent func-tions with varying argumentsrdquo International Journal of AppliedMathematics vol 8 no 3 pp 267ndash275 2002

[8] J M Jahangiri ldquoHarmonic functions starlike in the unit diskrdquoJournal of Mathematical Analysis and Applications vol 235 no2 pp 470ndash477 1999

[9] G Murugusundaramoorthy ldquoA class of Ruscheweyh-type har-monic univalent functions with varying argumentsrdquo SouthwestJournal of Pure and AppliedMathematics no 2 pp 90ndash95 2003

[10] S Ruscheweyh ldquoNew criteria for univalent functionsrdquo Proceed-ings of the American Mathematical Society vol 49 pp 109ndash1151975

[11] H A Al-Kharsani and R A Al-Khal ldquoUnivalent harmonicfunctionsrdquo Journal of Inequalities in Pure and Applied Mathe-matics vol 8 no 2 article 59 p 8 2007

[12] J Dziok and H M Srivastava ldquoClasses of analytic func-tions associated with the generalized hypergeometric functionrdquoApplied Mathematics and Computation vol 103 no 1 pp 1ndash131999

[13] S Ruscheweyh ldquoNeighborhoods of univalent functionsrdquo Pro-ceedings of the AmericanMathematical Society vol 81 no 4 pp521ndash527 1981

Submit your manuscripts athttpwwwhindawicom

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Differential EquationsInternational Journal of

Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

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Mathematical PhysicsAdvances in

Complex AnalysisJournal of

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OptimizationJournal of

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CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

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Operations ResearchAdvances in

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Function Spaces

Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of Mathematics and Mathematical Sciences

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Algebra

Discrete Dynamics in Nature and Society

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Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of

Page 2: HudaAldwebyandMaslinaDarus - downloads.hindawi.comdownloads.hindawi.com/archive/2013/382312.pdf · Correspondence should be addressed to Maslina Darus; maslina@ukm.my Received June

2 ISRNMathematical Analysis

We note that

lim119902rarr1

minus

[119903Φ119904(119902

1198861

119902

119886119903

119902

1198871

119902

119887119904

119902 (119902 minus 1)

1+119904minus119903119911)]

=119903119865119904(1198861 119886

119903 1198871 119887

119904 119911)

(4)

where119903119865119904(1198861 119886

119903 1198871 119887

119904 119911) is the well-known general-

ized hypergeometric function By the ratio test one observesthat for |119902| lt 1 and 119903 = 119904 + 1 the series defined in (2)converges absolutely in U so that it represented an analyticfunction in U For more mathematical background of basichypergeometric functions one may refer to [3 4]

The 119902-derivative of a function ℎ(119909) is defined by

119863119902 (ℎ (119909)) =

ℎ (119902119909) minus ℎ (119909)

(119902 minus 1) 119909

119902 = 1 119909 = 0 (5)

For a function ℎ(119911) = 119911119896 we can observe that

119863119902 (ℎ (119911)) = 119863119902

(119911

119896) =

1 minus 119902

119896

1 minus 119902

119911

119896minus1= [119896]119902

119911

119896minus1 (6)

Then lim119902rarr1

119863119902(ℎ(119911)) = lim

119902rarr1[119896]119902119911

119896minus1= 119896119911

119896minus1= ℎ

1015840(119911)

where ℎ1015840(119911) is the ordinary derivative For more properties of119863119902 see [4 5]Corresponding to the function

119903Φ119904(1198861 119886

119903 1198871 119887

119904

119902 119911) consider

119903G119904(1198861 119886

119903 1198871 119887

119904 119902 119911)

= 119911119903Φ119904(1198861 119886

119903 1198871 119887

119904 119902 119911)

= 119911 +

infin

sum

119896=2

(1198861 119902)

119896minus1sdot sdot sdot (119886119903 119902)

119896minus1

(119902 119902)

119896minus1(1198871 119902)

119896minus1sdot sdot sdot (119887119904 119902)

119896minus1

119911

119896

(7)

The authors [6] defined the linear operator 119867119903119904(1198861 119886

119903

1198871 119887

119904 119902)119891 A rarr A by

119867

119903

119904(1198861 119886

119903 1198871 119887

119904 119902) 119891 (119911)

=119903G119904(1198861 119886

119903 1198871 119887

119904 119902 119911) lowast 119891 (119911)

= 119911 +

infin

sum

119896=2

Γ (1198861 119902 119896) 119886

119896119911

119896

(8)

where (lowast) stands for convolution and

Γ (1198861 119902 119896) =

(1198861 119902)

119896minus1sdot sdot sdot (119886119903 119902)

119896minus1

(119902 119902)

119896minus1(1198871 119902)

119896minus1sdot sdot sdot (119887119904 119902)

119896minus1

(9)

To make the notation simple we write

119867

119903

119904[1198861 119902] 119891 (119911) = 119867

119903

119904(1198861 119886

119903 1198871 119887

119904 119902) 119891 (119911) (10)

We define the operator (8) of harmonic function 119891 = ℎ + 119892given by (1) as

119867

119903

119904[1198861 119902] 119891 (119911) = 119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911) (11)

Definition 1 For 0 le 120575 lt 1 let 119878lowast119867(1198861 120575 119902) denote the

subfamily of starlike harmonic functions 119891 isin 119878lowast119867of the form

(1) such that

120597

120597120579

(arg119867119903119904[1198861 119902] 119891) ge 120575 |119911| = 119903 lt 1 (12)

Following [7] a function 119891 is said to be in the class119881119867(1198861 120575 119902) = 119878

lowast

119867(1198861 120575 119902) cap 119881

119867if 119891 of the form (1) satisfies

the condition that

arg (119886119896) = 120579119896

arg (119887119896) = 120599119896 (119896 ge 119899 + 1 119899 isin N) (13)

and if there exists a real number 120588 such that

120579119896+ (119896 minus 1) 120601 equiv 120587 (mod 2120587) 120599

119896+ (119896 minus 1) 120601 equiv 0

(119896 ge 119899 + 1 119899 isin N) (14)

By specializing the parameters of 119867119903119904[1198861 119902]119891 we obtain

different classes of starlike harmonic functions for example

(i) for 119903 = 119904 + 1 1198862= 1198871 119886

119903= 119887119904 119878lowast119867(119902 119902 120575) =

119878119867(120575) [8] is the class of sense-preserving harmonicunivalent functions 119891 which are starlike of order 120575 inU that is 120597120597120579(arg119891(119903119890i120579)) ge 120575

(ii) for 119903 = 119904 + 1 1198862= 1198871 119886

119903= 119887119904 and 119886

1=

119902

119899+1 119902 rarr 1 119878lowast

119867(119902

119899+1 119902 120575) = 119877

119867(119899 120572) [9] is the

class of starlike harmonic univalent functions with(120597120597120579)(arg119863119899119891(119911)) ge 120575 where 119863 is the Ruscheweyhderivative (see [10])

(iii) for 119894 = 1 119903 119895 = 1 119904 119903 = 119904 + 1 119886119894= 119902

120572119894

and 119887119895= 119902

120573119895 119902 rarr 1 119878lowast

119867(1198861 119902 120575) = 119878

lowast

119867(1205721 120575) [11]

is the class of starlike harmonic univalent functionswith (120597120597120579)(arg119867119903

119904[1205721]119891) ge 120575 where 119867119903

119904[1205721] is the

Dziok-Srivastava operator (see [12])

2 Main Results

In our first theorem we introduce a sufficient coefficientbound for harmonic functions in 119878lowast

119867(1198861 120575 119902)

Theorem 2 Let 119891 = ℎ + 119892 be given by (1) If

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896)

le 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

(15)

where 1198861= 1 0 le 120575 lt 1 and Γ(119886

1 119902 119896) is given by (9) then

119891 isin 119878

lowast

119867(1198861 120575 119902)

ISRNMathematical Analysis 3

Proof To prove that 119891 isin 119878lowast119867(1198861 120575 119902) we only need to show

that if (15) holds then the required condition (12) is satisfiedFor (12) we can write

120597

120597120579

(arg119867119903119904[1198861 119902] 119891 (119911))

= R

119911119863119902(119867

119903

119904[1198861 119902] ℎ (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus

119911119863119902(119867

119903

119904[1198861 119902] 119892 (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

= R119860 (119911)

119861 (119911)

(16)

Using the fact that R(119908) ge 120575 if and only if |1 minus 120575 + 119908| ge|1 + 120575 minus 119908| it suffices to show that

|119860 (119911) + (1 minus 120575) 119861 (119911)| minus |119860 (119911) minus (1 + 120575) 119861 (119911)| ge 0 (17)

Substituting for 119860(119911) and 119861(119911) in (15) yields

|119860 (119911) + (1 minus 120575) 119861 (119911)| minus |119860 (119911) minus (1 + 120575) 119861 (119911)|

ge (2 minus 120575) |119911| minus

infin

sum

119896=2

([119896]119902+ 1 minus 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

|119911|

119896

minus

infin

sum

119896=1

([119896]119902minus 1 + 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

|119911|

119896

minus 120575 |119911| minus

infin

sum

119896=2

([119896]119902minus 1 minus 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

|119911|

119896

minus

infin

sum

119896=1

([119896]119902+ 1 + 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

|119911|

119896

ge 2 (1 minus 120575) |119911| 1 minus

infin

sum

119896=2

[119896]119902minus 120575

1 minus 120575

Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

minus

infin

sum

119896=1

[119896]119902+ 120575

1 minus 120575

Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

= 2 (1 minus 120575) |119911| 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

minus [

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

)]

times Γ (1198861 119902 119896)

(18)

The last expression is nonnegative by (15) and so 119891 isin

119878

lowast

119867(1198861 120575 119902)

Nowwe obtain the necessary and sufficient conditions for119891 = ℎ + g given by (14)

Theorem 3 Let 119891 = ℎ + 119892 be given by (11) Then 119891 isin

119881

119867(1198861 120575 119902) if and only if

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896)

le 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

(19)

where 1198861= 1 0 le 120575 lt 1 and Γ(119886

1 119902 119896) is given by (9)

Proof Since 119881

119867(1198861 120575 119902) sub 119878

lowast

119867(1198861 120575 119902) we only to

prove the only if part of the theorem So that for func-tions 119891 isin 119881

119867(1198861 120575 119902) we notice that the condition

(120597120597120579)(arg119867119903119904[1198861 119902]119891(119911)) ge 120575 is equivalent to

120597

120597120579

(arg119867119903119904[1198861 119902] 119891 (119911)) minus 120575

= R119911119863119902(119867

119903

119904[1198861 119902] ℎ (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus

119911119863119902(119867

119903

119904[1198861 119902] 119892 (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus120575 ge 0

(20)

That is

R[

[

(1 minus 120575) 119911 + sum

infin

119896=2([119896]119902

minus 120575) Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

119911

119896minus sum

infin

119896=1([119896]119902

+ 120575) Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

119911

119896

119911 + sum

infin

119896=2Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

119911

119896+ sum

infin

119896=1Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

119911

119896

]

]

ge 0 (21)

4 ISRNMathematical Analysis

The previous condition must hold for all values of 119911 in UUpon choosing 120601 according to (14) we must have

(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

minus

sum

infin

119896=2(([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

ge 0

(22)

If condition (19) does not hold then the numerator in (22)is negative for 119903 sufficiently close to 1 Hence there exist1199110= 1199030in (01) for which the quotient of (22) is negativeThis

contradicts the fact that 119891 isin 119881119867(1198861 120575 119902) and this completes

the proof

The following theorem gives the distortion bounds forfunctions in119881

119867(1198861 120575 119902)which yield a covering result for this

class

Theorem 4 If 119891 isin 119881119867(1198861 120575 119902) then

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

+

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

ge (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

minus

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

(23)

where

Γ (1198861 119902 2) =

(1 minus 1198861) sdot sdot sdot (1 minus 119886

119903)

(1 minus 119902) (1 minus 1198871) sdot sdot sdot (1 minus 119887

119904)

[2]119902= (119902 + 1)

(24)

Proof Wewill only prove the right hand inequalityThe prooffor the left hand inequality is similar

let 119891 isin 119881119867(1198861 120575 119902) Taking the absolute value of 119891 we

obtain

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

119896

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

2

(25)

That is

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ([2]119902

minus 120575)

times

infin

sum

119896=2

(

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

)

times Γ (1198861 119902 2) 119903

2

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ((119902 + 1) minus 120575)

times [1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

] 119903

2

= (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1

Γ (1198861 119902 2)

times [

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

2

(26)

Corollary 5 Let 119891 be of the form (1) so that 119891 isin 119881119867(1198861 120575 119902)

Then

119908 |119908| lt

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) minus 120575) Γ (1198861 119902 2)

minus

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) + 120575) Γ (1198861 119902 2)

1003816100381610038161003816

1198871

1003816100381610038161003816

sub 119891 (U)

(27)

Next one determines the extreme points of closed convex hullof 119881119867(1198861 120575 119902) denoted by clco119881

119867(1198861 120575 119902)

Theorem 6 Set

120582119896=

1 minus 120575

([119896]119902minus 120575) Γ (119886

1 119902 119896)

120583119896=

1 minus 120575

([119896]119902+ 120575) Γ (119886

1 119902 119896)

(28)

For 1198871fixed the extreme points for clco119881

119867(1198861 120575 119902) are

119911 + 120582119896119909119911

119896+ 1198871119911 cup 119911 + 119887

1119911 + 120583119896119909119911

119896 (29)

where 119896 ge 2 and |119909| = 1 minus |1198871|

Proof Any function 119891 isin clco119881119867(1198861 120575 119902) may be expressed

as

119891 (119911) = 119911 +

infin

sum

119896=2

1003816100381610038161003816

119886119896

1003816100381610038161003816

119890

119894120572119896

119911

119896+ 1198871119911 +

infin

sum

119896=2

1003816100381610038161003816

119887119896

1003816100381610038161003816

119890

119894120573119896

119911

119896 (30)

ISRNMathematical Analysis 5

where the coefficients satisfy the inequality (15) Set ℎ1(119911) =

119911 1198921(119911) = 119887

1119911 ℎ119896(119911) = 119911 + 120582

119896119890

119894120572119896

119911

119896 and 119892119896(119911) = 119887

1(119911) +

119890

119894120573119896

119911

119896 for 119896 = 2 3 Writing 119883119896= |119886119896|120582119896 119884119896= |119887119896|120583119896

119896 = 2 3 and1198831= 1minussum

infin

119896=2119883119896 1198841= 1minussum

infin

119896=2119884119896 we have

119891 (119911) =

infin

sum

119896=1

(119883119896ℎ119896 (119911) + 119884119896

119892119896 (119911)) (31)

In particular set

1198911 (119911) = 119911 + 1198871

119911 119891119896 (119911) = 119911 + 120582119896

119909119911

119896+ 1198871119911 + 120583119896119910119911

119896

(119896 ge 2 |119909| +

1003816100381610038161003816

119910

1003816100381610038161003816

= 1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(32)

Therefore the extreme points of clco119881119867(1198861 120575 119902) are

contained in 119891119896(119911) To see that 119891

1is not an extreme point

note that1198911may be written as a convex linear combination of

functions in clco119881119867(1198861 120575 119902) as follows

1198911 (119911) =

1

2

1198911 (119911) + 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

+

1

2

1198911 (119911) minus 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

(33)

If both |119909| = 0 and |119910| = 0 we will show that it can also beexpressed as a convex linear combination of functions inclco119881

119867(1198861 120575 119902) Without loss of generality assume that |119909| ge

|119910| Choose 120598 gt 0 small enough so that 120598 lt |119909||119910| Set119860 = 1 + 120598 and 119861 = 1 minus |120598119909119910| We then see that both

1199051 (119911) = 119911 + 120582119896

119860119909119911

119896+ 1198871119911 + 120583119896119910119861119911

119896

1199052 (119911) = 119911 + 120582119896 (

2 minus 119860) 119909119911

119896+ 1198871119911 + 120583119896119910 (2 minus 119861) 119911

119896

(34)

are in clco119881119867(1198861 120575 119902) and note that

119891119899 (119911) =

1

2

1199051 (119911) + 1199052 (

119911) (35)

The extremal coefficient bound shows that the functions ofthe form (29) are extreme points for clco119881

119867(1198861 120575 119902) and so

the proof is complete

Following the earlier works in [2 13] we refer to the 120574-neighborhood of the functions 119891 defined by (1) to be the setof functions 119865 for which

119873120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

119896 (

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

) +

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(36)

We define the 119902-120574-neighborhood of a function 119891 isin 119878119867as

follows

119873

119902

120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

[119896]119902(

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

)

+

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(37)

In our case let us define the generalized 119902-120574-neighborhood of 119891 to be the set

119873

119902

120574(119891) = 119865

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

]

+ (1 + 120575)

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le (1 minus 120575) 120574

(38)

Theorem 7 Let 119891 be given by (1) If 119891 satisfies the conditions

infin

sum

119896=2

[119896]119902([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

Γ (1198861 119902 119896)

+

infin

sum

1=2

[119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

Γ (1198861 119902 119896) le 1 minus 120575

0 le 120575 lt 1

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(39)

then119873119902120574(119891) sub 119878

lowast

119867(1198861 120575 119902)

Proof Let 119891 satisfy (39) and let

119865 (119911) = 119911 + 1198611119911 +

infin

sum

119896=2

(119860119896119911

119896+ 119861119896119911

119896) (40)

belong to119873119902120574(119891) We have

(1 + 120575)

1003816100381610038161003816

1198611

1003816100381610038161003816

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896

1003816100381610038161003816

]

le (1 + 120575)

1003816100381610038161003816

1198611minus 1198871

1003816100381610038161003816

+ (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

6 ISRNMathematical Analysis

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896minus 119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896minus 119887119896

1003816100381610038161003816

]

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

[2]119902minus 120575

infin

sum

119896=2

Γ (1198861 119902 119896) [[119896]119902

([119896]119902minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ [119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

(119902 + 1) minus 120575

times [(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

] le 1 minus 120575

(41)

Hence

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

119865 isin 119878

lowast

119867(1198861 120575 119902)

(42)

Acknowledgment

The work presented here was partially supported by LRGSTD2011UKMICT0302 and UKM-DLP-2011-050

References

[1] J Clunie and T Sheil-Small ldquoHarmonic univalent functionsrdquoAnnales Academiae Scientiarum Fennicae A vol 9 pp 3ndash251984

[2] Y Avcı and E Złotkiewicz ldquoOn harmonic univalent mappingsrdquoAnnales Universitatis Mariae Curie-Skłodowska A vol 44 pp1ndash7 1990

[3] G Gasper and M Rahman Basic Hypergeometric Series vol 35of Encyclopedia of Mathematics and Its Applications CambridgeUniversity Press Cambridge UK 1990

[4] H Exton q-hypergeometric functions and applications EllisHorwood Series Mathematics and its Applications Ellis Hor-wood Chichester UK 1983

[5] H A Ghany ldquo119902-derivative of basic hypergeometric series withrespect to parametersrdquo International Journal of MathematicalAnalysis vol 3 no 33-36 pp 1617ndash1632 2009

[6] A Mohammed and M Darus ldquoA generalized operator involv-ing the 119902-hypergeometric functionrdquoMatematicki Vesnik vol 65no 4 pp 454ndash465 2013

[7] J M Jahangiri and H Silverman ldquoHarmonic univalent func-tions with varying argumentsrdquo International Journal of AppliedMathematics vol 8 no 3 pp 267ndash275 2002

[8] J M Jahangiri ldquoHarmonic functions starlike in the unit diskrdquoJournal of Mathematical Analysis and Applications vol 235 no2 pp 470ndash477 1999

[9] G Murugusundaramoorthy ldquoA class of Ruscheweyh-type har-monic univalent functions with varying argumentsrdquo SouthwestJournal of Pure and AppliedMathematics no 2 pp 90ndash95 2003

[10] S Ruscheweyh ldquoNew criteria for univalent functionsrdquo Proceed-ings of the American Mathematical Society vol 49 pp 109ndash1151975

[11] H A Al-Kharsani and R A Al-Khal ldquoUnivalent harmonicfunctionsrdquo Journal of Inequalities in Pure and Applied Mathe-matics vol 8 no 2 article 59 p 8 2007

[12] J Dziok and H M Srivastava ldquoClasses of analytic func-tions associated with the generalized hypergeometric functionrdquoApplied Mathematics and Computation vol 103 no 1 pp 1ndash131999

[13] S Ruscheweyh ldquoNeighborhoods of univalent functionsrdquo Pro-ceedings of the AmericanMathematical Society vol 81 no 4 pp521ndash527 1981

Submit your manuscripts athttpwwwhindawicom

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Mathematical Problems in Engineering

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Differential EquationsInternational Journal of

Volume 2014

Applied MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

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Mathematical PhysicsAdvances in

Complex AnalysisJournal of

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OptimizationJournal of

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CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

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Operations ResearchAdvances in

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Function Spaces

Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of Mathematics and Mathematical Sciences

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Algebra

Discrete Dynamics in Nature and Society

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of

Page 3: HudaAldwebyandMaslinaDarus - downloads.hindawi.comdownloads.hindawi.com/archive/2013/382312.pdf · Correspondence should be addressed to Maslina Darus; maslina@ukm.my Received June

ISRNMathematical Analysis 3

Proof To prove that 119891 isin 119878lowast119867(1198861 120575 119902) we only need to show

that if (15) holds then the required condition (12) is satisfiedFor (12) we can write

120597

120597120579

(arg119867119903119904[1198861 119902] 119891 (119911))

= R

119911119863119902(119867

119903

119904[1198861 119902] ℎ (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus

119911119863119902(119867

119903

119904[1198861 119902] 119892 (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

= R119860 (119911)

119861 (119911)

(16)

Using the fact that R(119908) ge 120575 if and only if |1 minus 120575 + 119908| ge|1 + 120575 minus 119908| it suffices to show that

|119860 (119911) + (1 minus 120575) 119861 (119911)| minus |119860 (119911) minus (1 + 120575) 119861 (119911)| ge 0 (17)

Substituting for 119860(119911) and 119861(119911) in (15) yields

|119860 (119911) + (1 minus 120575) 119861 (119911)| minus |119860 (119911) minus (1 + 120575) 119861 (119911)|

ge (2 minus 120575) |119911| minus

infin

sum

119896=2

([119896]119902+ 1 minus 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

|119911|

119896

minus

infin

sum

119896=1

([119896]119902minus 1 + 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

|119911|

119896

minus 120575 |119911| minus

infin

sum

119896=2

([119896]119902minus 1 minus 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

|119911|

119896

minus

infin

sum

119896=1

([119896]119902+ 1 + 120575) Γ (119886

1 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

|119911|

119896

ge 2 (1 minus 120575) |119911| 1 minus

infin

sum

119896=2

[119896]119902minus 120575

1 minus 120575

Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

minus

infin

sum

119896=1

[119896]119902+ 120575

1 minus 120575

Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

= 2 (1 minus 120575) |119911| 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

minus [

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

)]

times Γ (1198861 119902 119896)

(18)

The last expression is nonnegative by (15) and so 119891 isin

119878

lowast

119867(1198861 120575 119902)

Nowwe obtain the necessary and sufficient conditions for119891 = ℎ + g given by (14)

Theorem 3 Let 119891 = ℎ + 119892 be given by (11) Then 119891 isin

119881

119867(1198861 120575 119902) if and only if

infin

sum

119896=2

(

[119896]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[119896]119902+ 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896)

le 1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

(19)

where 1198861= 1 0 le 120575 lt 1 and Γ(119886

1 119902 119896) is given by (9)

Proof Since 119881

119867(1198861 120575 119902) sub 119878

lowast

119867(1198861 120575 119902) we only to

prove the only if part of the theorem So that for func-tions 119891 isin 119881

119867(1198861 120575 119902) we notice that the condition

(120597120597120579)(arg119867119903119904[1198861 119902]119891(119911)) ge 120575 is equivalent to

120597

120597120579

(arg119867119903119904[1198861 119902] 119891 (119911)) minus 120575

= R119911119863119902(119867

119903

119904[1198861 119902] ℎ (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus

119911119863119902(119867

119903

119904[1198861 119902] 119892 (119911))

119867

119903

119904[1198861 119902] ℎ (119911) + 119867

119903

119904[1198861 119902] 119892 (119911)

minus120575 ge 0

(20)

That is

R[

[

(1 minus 120575) 119911 + sum

infin

119896=2([119896]119902

minus 120575) Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

119911

119896minus sum

infin

119896=1([119896]119902

+ 120575) Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

119911

119896

119911 + sum

infin

119896=2Γ (1198861 119902 119896)

1003816100381610038161003816

119886119896

1003816100381610038161003816

119911

119896+ sum

infin

119896=1Γ (1198861 119902 119896)

1003816100381610038161003816

119887119896

1003816100381610038161003816

119911

119896

]

]

ge 0 (21)

4 ISRNMathematical Analysis

The previous condition must hold for all values of 119911 in UUpon choosing 120601 according to (14) we must have

(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

minus

sum

infin

119896=2(([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

ge 0

(22)

If condition (19) does not hold then the numerator in (22)is negative for 119903 sufficiently close to 1 Hence there exist1199110= 1199030in (01) for which the quotient of (22) is negativeThis

contradicts the fact that 119891 isin 119881119867(1198861 120575 119902) and this completes

the proof

The following theorem gives the distortion bounds forfunctions in119881

119867(1198861 120575 119902)which yield a covering result for this

class

Theorem 4 If 119891 isin 119881119867(1198861 120575 119902) then

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

+

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

ge (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

minus

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

(23)

where

Γ (1198861 119902 2) =

(1 minus 1198861) sdot sdot sdot (1 minus 119886

119903)

(1 minus 119902) (1 minus 1198871) sdot sdot sdot (1 minus 119887

119904)

[2]119902= (119902 + 1)

(24)

Proof Wewill only prove the right hand inequalityThe prooffor the left hand inequality is similar

let 119891 isin 119881119867(1198861 120575 119902) Taking the absolute value of 119891 we

obtain

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

119896

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

2

(25)

That is

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ([2]119902

minus 120575)

times

infin

sum

119896=2

(

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

)

times Γ (1198861 119902 2) 119903

2

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ((119902 + 1) minus 120575)

times [1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

] 119903

2

= (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1

Γ (1198861 119902 2)

times [

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

2

(26)

Corollary 5 Let 119891 be of the form (1) so that 119891 isin 119881119867(1198861 120575 119902)

Then

119908 |119908| lt

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) minus 120575) Γ (1198861 119902 2)

minus

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) + 120575) Γ (1198861 119902 2)

1003816100381610038161003816

1198871

1003816100381610038161003816

sub 119891 (U)

(27)

Next one determines the extreme points of closed convex hullof 119881119867(1198861 120575 119902) denoted by clco119881

119867(1198861 120575 119902)

Theorem 6 Set

120582119896=

1 minus 120575

([119896]119902minus 120575) Γ (119886

1 119902 119896)

120583119896=

1 minus 120575

([119896]119902+ 120575) Γ (119886

1 119902 119896)

(28)

For 1198871fixed the extreme points for clco119881

119867(1198861 120575 119902) are

119911 + 120582119896119909119911

119896+ 1198871119911 cup 119911 + 119887

1119911 + 120583119896119909119911

119896 (29)

where 119896 ge 2 and |119909| = 1 minus |1198871|

Proof Any function 119891 isin clco119881119867(1198861 120575 119902) may be expressed

as

119891 (119911) = 119911 +

infin

sum

119896=2

1003816100381610038161003816

119886119896

1003816100381610038161003816

119890

119894120572119896

119911

119896+ 1198871119911 +

infin

sum

119896=2

1003816100381610038161003816

119887119896

1003816100381610038161003816

119890

119894120573119896

119911

119896 (30)

ISRNMathematical Analysis 5

where the coefficients satisfy the inequality (15) Set ℎ1(119911) =

119911 1198921(119911) = 119887

1119911 ℎ119896(119911) = 119911 + 120582

119896119890

119894120572119896

119911

119896 and 119892119896(119911) = 119887

1(119911) +

119890

119894120573119896

119911

119896 for 119896 = 2 3 Writing 119883119896= |119886119896|120582119896 119884119896= |119887119896|120583119896

119896 = 2 3 and1198831= 1minussum

infin

119896=2119883119896 1198841= 1minussum

infin

119896=2119884119896 we have

119891 (119911) =

infin

sum

119896=1

(119883119896ℎ119896 (119911) + 119884119896

119892119896 (119911)) (31)

In particular set

1198911 (119911) = 119911 + 1198871

119911 119891119896 (119911) = 119911 + 120582119896

119909119911

119896+ 1198871119911 + 120583119896119910119911

119896

(119896 ge 2 |119909| +

1003816100381610038161003816

119910

1003816100381610038161003816

= 1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(32)

Therefore the extreme points of clco119881119867(1198861 120575 119902) are

contained in 119891119896(119911) To see that 119891

1is not an extreme point

note that1198911may be written as a convex linear combination of

functions in clco119881119867(1198861 120575 119902) as follows

1198911 (119911) =

1

2

1198911 (119911) + 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

+

1

2

1198911 (119911) minus 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

(33)

If both |119909| = 0 and |119910| = 0 we will show that it can also beexpressed as a convex linear combination of functions inclco119881

119867(1198861 120575 119902) Without loss of generality assume that |119909| ge

|119910| Choose 120598 gt 0 small enough so that 120598 lt |119909||119910| Set119860 = 1 + 120598 and 119861 = 1 minus |120598119909119910| We then see that both

1199051 (119911) = 119911 + 120582119896

119860119909119911

119896+ 1198871119911 + 120583119896119910119861119911

119896

1199052 (119911) = 119911 + 120582119896 (

2 minus 119860) 119909119911

119896+ 1198871119911 + 120583119896119910 (2 minus 119861) 119911

119896

(34)

are in clco119881119867(1198861 120575 119902) and note that

119891119899 (119911) =

1

2

1199051 (119911) + 1199052 (

119911) (35)

The extremal coefficient bound shows that the functions ofthe form (29) are extreme points for clco119881

119867(1198861 120575 119902) and so

the proof is complete

Following the earlier works in [2 13] we refer to the 120574-neighborhood of the functions 119891 defined by (1) to be the setof functions 119865 for which

119873120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

119896 (

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

) +

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(36)

We define the 119902-120574-neighborhood of a function 119891 isin 119878119867as

follows

119873

119902

120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

[119896]119902(

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

)

+

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(37)

In our case let us define the generalized 119902-120574-neighborhood of 119891 to be the set

119873

119902

120574(119891) = 119865

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

]

+ (1 + 120575)

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le (1 minus 120575) 120574

(38)

Theorem 7 Let 119891 be given by (1) If 119891 satisfies the conditions

infin

sum

119896=2

[119896]119902([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

Γ (1198861 119902 119896)

+

infin

sum

1=2

[119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

Γ (1198861 119902 119896) le 1 minus 120575

0 le 120575 lt 1

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(39)

then119873119902120574(119891) sub 119878

lowast

119867(1198861 120575 119902)

Proof Let 119891 satisfy (39) and let

119865 (119911) = 119911 + 1198611119911 +

infin

sum

119896=2

(119860119896119911

119896+ 119861119896119911

119896) (40)

belong to119873119902120574(119891) We have

(1 + 120575)

1003816100381610038161003816

1198611

1003816100381610038161003816

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896

1003816100381610038161003816

]

le (1 + 120575)

1003816100381610038161003816

1198611minus 1198871

1003816100381610038161003816

+ (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

6 ISRNMathematical Analysis

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896minus 119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896minus 119887119896

1003816100381610038161003816

]

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

[2]119902minus 120575

infin

sum

119896=2

Γ (1198861 119902 119896) [[119896]119902

([119896]119902minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ [119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

(119902 + 1) minus 120575

times [(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

] le 1 minus 120575

(41)

Hence

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

119865 isin 119878

lowast

119867(1198861 120575 119902)

(42)

Acknowledgment

The work presented here was partially supported by LRGSTD2011UKMICT0302 and UKM-DLP-2011-050

References

[1] J Clunie and T Sheil-Small ldquoHarmonic univalent functionsrdquoAnnales Academiae Scientiarum Fennicae A vol 9 pp 3ndash251984

[2] Y Avcı and E Złotkiewicz ldquoOn harmonic univalent mappingsrdquoAnnales Universitatis Mariae Curie-Skłodowska A vol 44 pp1ndash7 1990

[3] G Gasper and M Rahman Basic Hypergeometric Series vol 35of Encyclopedia of Mathematics and Its Applications CambridgeUniversity Press Cambridge UK 1990

[4] H Exton q-hypergeometric functions and applications EllisHorwood Series Mathematics and its Applications Ellis Hor-wood Chichester UK 1983

[5] H A Ghany ldquo119902-derivative of basic hypergeometric series withrespect to parametersrdquo International Journal of MathematicalAnalysis vol 3 no 33-36 pp 1617ndash1632 2009

[6] A Mohammed and M Darus ldquoA generalized operator involv-ing the 119902-hypergeometric functionrdquoMatematicki Vesnik vol 65no 4 pp 454ndash465 2013

[7] J M Jahangiri and H Silverman ldquoHarmonic univalent func-tions with varying argumentsrdquo International Journal of AppliedMathematics vol 8 no 3 pp 267ndash275 2002

[8] J M Jahangiri ldquoHarmonic functions starlike in the unit diskrdquoJournal of Mathematical Analysis and Applications vol 235 no2 pp 470ndash477 1999

[9] G Murugusundaramoorthy ldquoA class of Ruscheweyh-type har-monic univalent functions with varying argumentsrdquo SouthwestJournal of Pure and AppliedMathematics no 2 pp 90ndash95 2003

[10] S Ruscheweyh ldquoNew criteria for univalent functionsrdquo Proceed-ings of the American Mathematical Society vol 49 pp 109ndash1151975

[11] H A Al-Kharsani and R A Al-Khal ldquoUnivalent harmonicfunctionsrdquo Journal of Inequalities in Pure and Applied Mathe-matics vol 8 no 2 article 59 p 8 2007

[12] J Dziok and H M Srivastava ldquoClasses of analytic func-tions associated with the generalized hypergeometric functionrdquoApplied Mathematics and Computation vol 103 no 1 pp 1ndash131999

[13] S Ruscheweyh ldquoNeighborhoods of univalent functionsrdquo Pro-ceedings of the AmericanMathematical Society vol 81 no 4 pp521ndash527 1981

Submit your manuscripts athttpwwwhindawicom

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Volume 2014

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Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Mathematical PhysicsAdvances in

Complex AnalysisJournal of

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OptimizationJournal of

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CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

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Operations ResearchAdvances in

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Function Spaces

Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of Mathematics and Mathematical Sciences

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

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Discrete Dynamics in Nature and Society

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Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of

Page 4: HudaAldwebyandMaslinaDarus - downloads.hindawi.comdownloads.hindawi.com/archive/2013/382312.pdf · Correspondence should be addressed to Maslina Darus; maslina@ukm.my Received June

4 ISRNMathematical Analysis

The previous condition must hold for all values of 119911 in UUpon choosing 120601 according to (14) we must have

(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

minus

sum

infin

119896=2(([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

+ sum

infin

119896=2(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) Γ (1198861 119902 119896) 119903

119896minus1

ge 0

(22)

If condition (19) does not hold then the numerator in (22)is negative for 119903 sufficiently close to 1 Hence there exist1199110= 1199030in (01) for which the quotient of (22) is negativeThis

contradicts the fact that 119891 isin 119881119867(1198861 120575 119902) and this completes

the proof

The following theorem gives the distortion bounds forfunctions in119881

119867(1198861 120575 119902)which yield a covering result for this

class

Theorem 4 If 119891 isin 119881119867(1198861 120575 119902) then

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

+

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

ge (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

minus

1

Γ (1198861 119902 2)

(

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

) 119903

2

|119911| = 119903 lt 1

(23)

where

Γ (1198861 119902 2) =

(1 minus 1198861) sdot sdot sdot (1 minus 119886

119903)

(1 minus 119902) (1 minus 1198871) sdot sdot sdot (1 minus 119887

119904)

[2]119902= (119902 + 1)

(24)

Proof Wewill only prove the right hand inequalityThe prooffor the left hand inequality is similar

let 119891 isin 119881119867(1198861 120575 119902) Taking the absolute value of 119891 we

obtain

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

119896

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

infin

sum

119896=2

(

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896

1003816100381610038161003816

) 119903

2

(25)

That is

1003816100381610038161003816

119891 (119911)

1003816100381610038161003816

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ([2]119902

minus 120575)

times

infin

sum

119896=2

(

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119886119896

1003816100381610038161003816

+

[2]119902minus 120575

1 minus 120575

1003816100381610038161003816

119887119896

1003816100381610038161003816

)

times Γ (1198861 119902 2) 119903

2

le (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1 minus 120575

Γ (1198861 119902 2) ((119902 + 1) minus 120575)

times [1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

] 119903

2

= (1 +

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903 +

1

Γ (1198861 119902 2)

times [

1 minus 120575

(119902 + 1) minus 120575

minus

1 + 120575

(119902 + 1) minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119903

2

(26)

Corollary 5 Let 119891 be of the form (1) so that 119891 isin 119881119867(1198861 120575 119902)

Then

119908 |119908| lt

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) minus 120575) Γ (1198861 119902 2)

minus

2Γ (1198861 119902 2) minus 1 minus (Γ (119886

1 119902 2) minus 1) 120575

((119902 + 1) + 120575) Γ (1198861 119902 2)

1003816100381610038161003816

1198871

1003816100381610038161003816

sub 119891 (U)

(27)

Next one determines the extreme points of closed convex hullof 119881119867(1198861 120575 119902) denoted by clco119881

119867(1198861 120575 119902)

Theorem 6 Set

120582119896=

1 minus 120575

([119896]119902minus 120575) Γ (119886

1 119902 119896)

120583119896=

1 minus 120575

([119896]119902+ 120575) Γ (119886

1 119902 119896)

(28)

For 1198871fixed the extreme points for clco119881

119867(1198861 120575 119902) are

119911 + 120582119896119909119911

119896+ 1198871119911 cup 119911 + 119887

1119911 + 120583119896119909119911

119896 (29)

where 119896 ge 2 and |119909| = 1 minus |1198871|

Proof Any function 119891 isin clco119881119867(1198861 120575 119902) may be expressed

as

119891 (119911) = 119911 +

infin

sum

119896=2

1003816100381610038161003816

119886119896

1003816100381610038161003816

119890

119894120572119896

119911

119896+ 1198871119911 +

infin

sum

119896=2

1003816100381610038161003816

119887119896

1003816100381610038161003816

119890

119894120573119896

119911

119896 (30)

ISRNMathematical Analysis 5

where the coefficients satisfy the inequality (15) Set ℎ1(119911) =

119911 1198921(119911) = 119887

1119911 ℎ119896(119911) = 119911 + 120582

119896119890

119894120572119896

119911

119896 and 119892119896(119911) = 119887

1(119911) +

119890

119894120573119896

119911

119896 for 119896 = 2 3 Writing 119883119896= |119886119896|120582119896 119884119896= |119887119896|120583119896

119896 = 2 3 and1198831= 1minussum

infin

119896=2119883119896 1198841= 1minussum

infin

119896=2119884119896 we have

119891 (119911) =

infin

sum

119896=1

(119883119896ℎ119896 (119911) + 119884119896

119892119896 (119911)) (31)

In particular set

1198911 (119911) = 119911 + 1198871

119911 119891119896 (119911) = 119911 + 120582119896

119909119911

119896+ 1198871119911 + 120583119896119910119911

119896

(119896 ge 2 |119909| +

1003816100381610038161003816

119910

1003816100381610038161003816

= 1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(32)

Therefore the extreme points of clco119881119867(1198861 120575 119902) are

contained in 119891119896(119911) To see that 119891

1is not an extreme point

note that1198911may be written as a convex linear combination of

functions in clco119881119867(1198861 120575 119902) as follows

1198911 (119911) =

1

2

1198911 (119911) + 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

+

1

2

1198911 (119911) minus 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

(33)

If both |119909| = 0 and |119910| = 0 we will show that it can also beexpressed as a convex linear combination of functions inclco119881

119867(1198861 120575 119902) Without loss of generality assume that |119909| ge

|119910| Choose 120598 gt 0 small enough so that 120598 lt |119909||119910| Set119860 = 1 + 120598 and 119861 = 1 minus |120598119909119910| We then see that both

1199051 (119911) = 119911 + 120582119896

119860119909119911

119896+ 1198871119911 + 120583119896119910119861119911

119896

1199052 (119911) = 119911 + 120582119896 (

2 minus 119860) 119909119911

119896+ 1198871119911 + 120583119896119910 (2 minus 119861) 119911

119896

(34)

are in clco119881119867(1198861 120575 119902) and note that

119891119899 (119911) =

1

2

1199051 (119911) + 1199052 (

119911) (35)

The extremal coefficient bound shows that the functions ofthe form (29) are extreme points for clco119881

119867(1198861 120575 119902) and so

the proof is complete

Following the earlier works in [2 13] we refer to the 120574-neighborhood of the functions 119891 defined by (1) to be the setof functions 119865 for which

119873120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

119896 (

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

) +

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(36)

We define the 119902-120574-neighborhood of a function 119891 isin 119878119867as

follows

119873

119902

120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

[119896]119902(

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

)

+

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(37)

In our case let us define the generalized 119902-120574-neighborhood of 119891 to be the set

119873

119902

120574(119891) = 119865

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

]

+ (1 + 120575)

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le (1 minus 120575) 120574

(38)

Theorem 7 Let 119891 be given by (1) If 119891 satisfies the conditions

infin

sum

119896=2

[119896]119902([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

Γ (1198861 119902 119896)

+

infin

sum

1=2

[119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

Γ (1198861 119902 119896) le 1 minus 120575

0 le 120575 lt 1

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(39)

then119873119902120574(119891) sub 119878

lowast

119867(1198861 120575 119902)

Proof Let 119891 satisfy (39) and let

119865 (119911) = 119911 + 1198611119911 +

infin

sum

119896=2

(119860119896119911

119896+ 119861119896119911

119896) (40)

belong to119873119902120574(119891) We have

(1 + 120575)

1003816100381610038161003816

1198611

1003816100381610038161003816

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896

1003816100381610038161003816

]

le (1 + 120575)

1003816100381610038161003816

1198611minus 1198871

1003816100381610038161003816

+ (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

6 ISRNMathematical Analysis

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896minus 119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896minus 119887119896

1003816100381610038161003816

]

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

[2]119902minus 120575

infin

sum

119896=2

Γ (1198861 119902 119896) [[119896]119902

([119896]119902minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ [119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

(119902 + 1) minus 120575

times [(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

] le 1 minus 120575

(41)

Hence

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

119865 isin 119878

lowast

119867(1198861 120575 119902)

(42)

Acknowledgment

The work presented here was partially supported by LRGSTD2011UKMICT0302 and UKM-DLP-2011-050

References

[1] J Clunie and T Sheil-Small ldquoHarmonic univalent functionsrdquoAnnales Academiae Scientiarum Fennicae A vol 9 pp 3ndash251984

[2] Y Avcı and E Złotkiewicz ldquoOn harmonic univalent mappingsrdquoAnnales Universitatis Mariae Curie-Skłodowska A vol 44 pp1ndash7 1990

[3] G Gasper and M Rahman Basic Hypergeometric Series vol 35of Encyclopedia of Mathematics and Its Applications CambridgeUniversity Press Cambridge UK 1990

[4] H Exton q-hypergeometric functions and applications EllisHorwood Series Mathematics and its Applications Ellis Hor-wood Chichester UK 1983

[5] H A Ghany ldquo119902-derivative of basic hypergeometric series withrespect to parametersrdquo International Journal of MathematicalAnalysis vol 3 no 33-36 pp 1617ndash1632 2009

[6] A Mohammed and M Darus ldquoA generalized operator involv-ing the 119902-hypergeometric functionrdquoMatematicki Vesnik vol 65no 4 pp 454ndash465 2013

[7] J M Jahangiri and H Silverman ldquoHarmonic univalent func-tions with varying argumentsrdquo International Journal of AppliedMathematics vol 8 no 3 pp 267ndash275 2002

[8] J M Jahangiri ldquoHarmonic functions starlike in the unit diskrdquoJournal of Mathematical Analysis and Applications vol 235 no2 pp 470ndash477 1999

[9] G Murugusundaramoorthy ldquoA class of Ruscheweyh-type har-monic univalent functions with varying argumentsrdquo SouthwestJournal of Pure and AppliedMathematics no 2 pp 90ndash95 2003

[10] S Ruscheweyh ldquoNew criteria for univalent functionsrdquo Proceed-ings of the American Mathematical Society vol 49 pp 109ndash1151975

[11] H A Al-Kharsani and R A Al-Khal ldquoUnivalent harmonicfunctionsrdquo Journal of Inequalities in Pure and Applied Mathe-matics vol 8 no 2 article 59 p 8 2007

[12] J Dziok and H M Srivastava ldquoClasses of analytic func-tions associated with the generalized hypergeometric functionrdquoApplied Mathematics and Computation vol 103 no 1 pp 1ndash131999

[13] S Ruscheweyh ldquoNeighborhoods of univalent functionsrdquo Pro-ceedings of the AmericanMathematical Society vol 81 no 4 pp521ndash527 1981

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical Problems in Engineering

Hindawi Publishing Corporationhttpwwwhindawicom

Differential EquationsInternational Journal of

Volume 2014

Applied MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical PhysicsAdvances in

Complex AnalysisJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OptimizationJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Operations ResearchAdvances in

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Function Spaces

Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of Mathematics and Mathematical Sciences

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Algebra

Discrete Dynamics in Nature and Society

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Decision SciencesAdvances in

Discrete MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of

Page 5: HudaAldwebyandMaslinaDarus - downloads.hindawi.comdownloads.hindawi.com/archive/2013/382312.pdf · Correspondence should be addressed to Maslina Darus; maslina@ukm.my Received June

ISRNMathematical Analysis 5

where the coefficients satisfy the inequality (15) Set ℎ1(119911) =

119911 1198921(119911) = 119887

1119911 ℎ119896(119911) = 119911 + 120582

119896119890

119894120572119896

119911

119896 and 119892119896(119911) = 119887

1(119911) +

119890

119894120573119896

119911

119896 for 119896 = 2 3 Writing 119883119896= |119886119896|120582119896 119884119896= |119887119896|120583119896

119896 = 2 3 and1198831= 1minussum

infin

119896=2119883119896 1198841= 1minussum

infin

119896=2119884119896 we have

119891 (119911) =

infin

sum

119896=1

(119883119896ℎ119896 (119911) + 119884119896

119892119896 (119911)) (31)

In particular set

1198911 (119911) = 119911 + 1198871

119911 119891119896 (119911) = 119911 + 120582119896

119909119911

119896+ 1198871119911 + 120583119896119910119911

119896

(119896 ge 2 |119909| +

1003816100381610038161003816

119910

1003816100381610038161003816

= 1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(32)

Therefore the extreme points of clco119881119867(1198861 120575 119902) are

contained in 119891119896(119911) To see that 119891

1is not an extreme point

note that1198911may be written as a convex linear combination of

functions in clco119881119867(1198861 120575 119902) as follows

1198911 (119911) =

1

2

1198911 (119911) + 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

+

1

2

1198911 (119911) minus 1205822

(1 minus

1003816100381610038161003816

1198871

1003816100381610038161003816

) 119911

2

(33)

If both |119909| = 0 and |119910| = 0 we will show that it can also beexpressed as a convex linear combination of functions inclco119881

119867(1198861 120575 119902) Without loss of generality assume that |119909| ge

|119910| Choose 120598 gt 0 small enough so that 120598 lt |119909||119910| Set119860 = 1 + 120598 and 119861 = 1 minus |120598119909119910| We then see that both

1199051 (119911) = 119911 + 120582119896

119860119909119911

119896+ 1198871119911 + 120583119896119910119861119911

119896

1199052 (119911) = 119911 + 120582119896 (

2 minus 119860) 119909119911

119896+ 1198871119911 + 120583119896119910 (2 minus 119861) 119911

119896

(34)

are in clco119881119867(1198861 120575 119902) and note that

119891119899 (119911) =

1

2

1199051 (119911) + 1199052 (

119911) (35)

The extremal coefficient bound shows that the functions ofthe form (29) are extreme points for clco119881

119867(1198861 120575 119902) and so

the proof is complete

Following the earlier works in [2 13] we refer to the 120574-neighborhood of the functions 119891 defined by (1) to be the setof functions 119865 for which

119873120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

119896 (

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

) +

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(36)

We define the 119902-120574-neighborhood of a function 119891 isin 119878119867as

follows

119873

119902

120574(119891) = 119865 = 119911 +

infin

sum

119896=2

119860119896119911

119896+

infin

sum

119896=1

119861119896119911

119896

infin

sum

119896=2

[119896]119902(

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

)

+

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le 120574

(37)

In our case let us define the generalized 119902-120574-neighborhood of 119891 to be the set

119873

119902

120574(119891) = 119865

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896minus 119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896minus 119861119896

1003816100381610038161003816

]

+ (1 + 120575)

1003816100381610038161003816

1198871minus 1198611

1003816100381610038161003816

le (1 minus 120575) 120574

(38)

Theorem 7 Let 119891 be given by (1) If 119891 satisfies the conditions

infin

sum

119896=2

[119896]119902([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

Γ (1198861 119902 119896)

+

infin

sum

1=2

[119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

Γ (1198861 119902 119896) le 1 minus 120575

0 le 120575 lt 1

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

(39)

then119873119902120574(119891) sub 119878

lowast

119867(1198861 120575 119902)

Proof Let 119891 satisfy (39) and let

119865 (119911) = 119911 + 1198611119911 +

infin

sum

119896=2

(119860119896119911

119896+ 119861119896119911

119896) (40)

belong to119873119902120574(119891) We have

(1 + 120575)

1003816100381610038161003816

1198611

1003816100381610038161003816

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896

1003816100381610038161003816

]

le (1 + 120575)

1003816100381610038161003816

1198611minus 1198871

1003816100381610038161003816

+ (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

6 ISRNMathematical Analysis

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896minus 119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896minus 119887119896

1003816100381610038161003816

]

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

[2]119902minus 120575

infin

sum

119896=2

Γ (1198861 119902 119896) [[119896]119902

([119896]119902minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ [119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

(119902 + 1) minus 120575

times [(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

] le 1 minus 120575

(41)

Hence

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

119865 isin 119878

lowast

119867(1198861 120575 119902)

(42)

Acknowledgment

The work presented here was partially supported by LRGSTD2011UKMICT0302 and UKM-DLP-2011-050

References

[1] J Clunie and T Sheil-Small ldquoHarmonic univalent functionsrdquoAnnales Academiae Scientiarum Fennicae A vol 9 pp 3ndash251984

[2] Y Avcı and E Złotkiewicz ldquoOn harmonic univalent mappingsrdquoAnnales Universitatis Mariae Curie-Skłodowska A vol 44 pp1ndash7 1990

[3] G Gasper and M Rahman Basic Hypergeometric Series vol 35of Encyclopedia of Mathematics and Its Applications CambridgeUniversity Press Cambridge UK 1990

[4] H Exton q-hypergeometric functions and applications EllisHorwood Series Mathematics and its Applications Ellis Hor-wood Chichester UK 1983

[5] H A Ghany ldquo119902-derivative of basic hypergeometric series withrespect to parametersrdquo International Journal of MathematicalAnalysis vol 3 no 33-36 pp 1617ndash1632 2009

[6] A Mohammed and M Darus ldquoA generalized operator involv-ing the 119902-hypergeometric functionrdquoMatematicki Vesnik vol 65no 4 pp 454ndash465 2013

[7] J M Jahangiri and H Silverman ldquoHarmonic univalent func-tions with varying argumentsrdquo International Journal of AppliedMathematics vol 8 no 3 pp 267ndash275 2002

[8] J M Jahangiri ldquoHarmonic functions starlike in the unit diskrdquoJournal of Mathematical Analysis and Applications vol 235 no2 pp 470ndash477 1999

[9] G Murugusundaramoorthy ldquoA class of Ruscheweyh-type har-monic univalent functions with varying argumentsrdquo SouthwestJournal of Pure and AppliedMathematics no 2 pp 90ndash95 2003

[10] S Ruscheweyh ldquoNew criteria for univalent functionsrdquo Proceed-ings of the American Mathematical Society vol 49 pp 109ndash1151975

[11] H A Al-Kharsani and R A Al-Khal ldquoUnivalent harmonicfunctionsrdquo Journal of Inequalities in Pure and Applied Mathe-matics vol 8 no 2 article 59 p 8 2007

[12] J Dziok and H M Srivastava ldquoClasses of analytic func-tions associated with the generalized hypergeometric functionrdquoApplied Mathematics and Computation vol 103 no 1 pp 1ndash131999

[13] S Ruscheweyh ldquoNeighborhoods of univalent functionsrdquo Pro-ceedings of the AmericanMathematical Society vol 81 no 4 pp521ndash527 1981

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical Problems in Engineering

Hindawi Publishing Corporationhttpwwwhindawicom

Differential EquationsInternational Journal of

Volume 2014

Applied MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical PhysicsAdvances in

Complex AnalysisJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OptimizationJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Operations ResearchAdvances in

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Function Spaces

Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of Mathematics and Mathematical Sciences

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Algebra

Discrete Dynamics in Nature and Society

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Decision SciencesAdvances in

Discrete MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of

Page 6: HudaAldwebyandMaslinaDarus - downloads.hindawi.comdownloads.hindawi.com/archive/2013/382312.pdf · Correspondence should be addressed to Maslina Darus; maslina@ukm.my Received June

6 ISRNMathematical Analysis

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119860119896minus 119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119861119896minus 119887119896

1003816100381610038161003816

]

+

infin

sum

119896=2

Γ (1198861 119902 119896) [([119896]119902

minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ ([119896]119902+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

[2]119902minus 120575

infin

sum

119896=2

Γ (1198861 119902 119896) [[119896]119902

([119896]119902minus 120575)

1003816100381610038161003816

119886119896

1003816100381610038161003816

+ [119896]119902([119896]119902

+ 120575)

1003816100381610038161003816

119887119896

1003816100381610038161003816

]

le (1 minus 120575) 120574 + (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

+

1

(119902 + 1) minus 120575

times [(1 minus 120575) minus (1 + 120575)

1003816100381610038161003816

1198871

1003816100381610038161003816

] le 1 minus 120575

(41)

Hence

120574 le

1 minus 120575

(119902 + 1) minus 120575

(1 minus

1 + 120575

1 minus 120575

1003816100381610038161003816

1198871

1003816100381610038161003816

)

119865 isin 119878

lowast

119867(1198861 120575 119902)

(42)

Acknowledgment

The work presented here was partially supported by LRGSTD2011UKMICT0302 and UKM-DLP-2011-050

References

[1] J Clunie and T Sheil-Small ldquoHarmonic univalent functionsrdquoAnnales Academiae Scientiarum Fennicae A vol 9 pp 3ndash251984

[2] Y Avcı and E Złotkiewicz ldquoOn harmonic univalent mappingsrdquoAnnales Universitatis Mariae Curie-Skłodowska A vol 44 pp1ndash7 1990

[3] G Gasper and M Rahman Basic Hypergeometric Series vol 35of Encyclopedia of Mathematics and Its Applications CambridgeUniversity Press Cambridge UK 1990

[4] H Exton q-hypergeometric functions and applications EllisHorwood Series Mathematics and its Applications Ellis Hor-wood Chichester UK 1983

[5] H A Ghany ldquo119902-derivative of basic hypergeometric series withrespect to parametersrdquo International Journal of MathematicalAnalysis vol 3 no 33-36 pp 1617ndash1632 2009

[6] A Mohammed and M Darus ldquoA generalized operator involv-ing the 119902-hypergeometric functionrdquoMatematicki Vesnik vol 65no 4 pp 454ndash465 2013

[7] J M Jahangiri and H Silverman ldquoHarmonic univalent func-tions with varying argumentsrdquo International Journal of AppliedMathematics vol 8 no 3 pp 267ndash275 2002

[8] J M Jahangiri ldquoHarmonic functions starlike in the unit diskrdquoJournal of Mathematical Analysis and Applications vol 235 no2 pp 470ndash477 1999

[9] G Murugusundaramoorthy ldquoA class of Ruscheweyh-type har-monic univalent functions with varying argumentsrdquo SouthwestJournal of Pure and AppliedMathematics no 2 pp 90ndash95 2003

[10] S Ruscheweyh ldquoNew criteria for univalent functionsrdquo Proceed-ings of the American Mathematical Society vol 49 pp 109ndash1151975

[11] H A Al-Kharsani and R A Al-Khal ldquoUnivalent harmonicfunctionsrdquo Journal of Inequalities in Pure and Applied Mathe-matics vol 8 no 2 article 59 p 8 2007

[12] J Dziok and H M Srivastava ldquoClasses of analytic func-tions associated with the generalized hypergeometric functionrdquoApplied Mathematics and Computation vol 103 no 1 pp 1ndash131999

[13] S Ruscheweyh ldquoNeighborhoods of univalent functionsrdquo Pro-ceedings of the AmericanMathematical Society vol 81 no 4 pp521ndash527 1981

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical Problems in Engineering

Hindawi Publishing Corporationhttpwwwhindawicom

Differential EquationsInternational Journal of

Volume 2014

Applied MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical PhysicsAdvances in

Complex AnalysisJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OptimizationJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Operations ResearchAdvances in

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Function Spaces

Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of Mathematics and Mathematical Sciences

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Algebra

Discrete Dynamics in Nature and Society

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Decision SciencesAdvances in

Discrete MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of

Page 7: HudaAldwebyandMaslinaDarus - downloads.hindawi.comdownloads.hindawi.com/archive/2013/382312.pdf · Correspondence should be addressed to Maslina Darus; maslina@ukm.my Received June

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical Problems in Engineering

Hindawi Publishing Corporationhttpwwwhindawicom

Differential EquationsInternational Journal of

Volume 2014

Applied MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Mathematical PhysicsAdvances in

Complex AnalysisJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OptimizationJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Operations ResearchAdvances in

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Function Spaces

Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of Mathematics and Mathematical Sciences

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Algebra

Discrete Dynamics in Nature and Society

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Decision SciencesAdvances in

Discrete MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of