Phng GD&T thnh ph Lo Cai K THI CHN LC HC SINH GII TNH Trng THCS L T Trng GII TON TRN MY TNH CM TAY

KHI 9 THCS - NM HC 2010 - 2011

Thi gian lm bi : 150 pht - Ngy thi : 14/09/2010.

Ch : - thi gm 5 trang

- Th sinh lm bi trc tip vo bn thi ny.

- Nu khng ni g thm , hy tnh chnh xc n 4 ch s l

thp phn.

Bi 1 : ( 5 im ) Tnh gi tr ca biu thc :

Bit

Bi 2 : ( 5 im ) Cho a thc c gi tr l :

- 14 ; - 9 ; 0 ; 13 ; 30 khi x ln lt nhn cc gi tr 1 ; 2 ; 3 ; 4 ; 5 .

a) Tm biu thc hm ca a thc .b) Tnh gi tr chnh xc ca .Bi 3 : ( 5 im )

a) S chnh phng P c dng . Tm cc ch s a,b,c bit rng .b) S chnh phng Q c dng . Tm cc ch s c,d bit rng tng cc ch s ca Q chia ht cho 5. Nu s lc qui trnh bm phm.

Bi 4 : ( 5 im ) Ba vi nc cng chy vo b ban u cha c nc sau eq \s\don1(\f(315,193)) gi th y b.

Bit rng, nu chy mt mnh vo b cha c nc th vi th hai chy chm hn

vi th nht 30 pht; vi th ba chy chm hn vi th hai 15 pht. Tnh thi gian

chy mt mnh y b ca mi vi nc . Bi 5 : ( 5 im ) Cho cc a thc :

V .a) Phn tch cc a thc v thnh nhn t.

b) Tm nghim chnh xc hoc gn ng ca phng trnh : .

Bi 6 : ( 5 im )

Tm cc ch s hng n v, hng chc v hng trm ca s t nhin :

.

Bi 7 : ( 5 im )

Cho dy hai s xc nh bi :

;

a) Tnh cc gi tr chnh xc ca ueq \l(\o\ac( ,3)) , ueq \l(\o\ac( ,4)) , ueq \l(\o\ac( ,15)) , ueq \l(\o\ac( ,16)) , ueq \l(\o\ac( ,17)) , ueq \l(\o\ac( ,18)) , ueq \l(\o\ac( ,19)) , ueq \l(\o\ac( ,20)) .

Vit quy trnh bm phm.

b) Lp cng thc truy hi tnh ueq \l(\o\ac( ,n+2)) theo mt biu thc bc nht i vi ueq \l(\o\ac( ,n+1)) v ueq \l(\o\ac( ,n)) .Chng minh.

Bi 8 : ( 5 im )

Cho hnh chp ng gic u S.ABCDE , cnh y , cnh bn .

a) Tnh gn ng din tch a gic y ABCDE.

b) Tnh gn ng din tch xung quanh c) v th tch ca hnh chp S.ABCDE.

Bi 9 : ( 5 im ) Bc An gi tit kim s tin ban u l 20 triu ng theo k hn 3 thng vi li sut 0,72% / thng . sau mt nm, bc An rt c vn l li v gi li theo k hn 6 thng vi li sut 0,78% / thng. Gi ng mt s k hn 6 thng v thm mt thng na th bc An phi rt tin trc k hn sa cha nh, c s tin l 29451583,0849007 ng ( cha lm trn ). Hi bc An gi bao nhiu k hn 6 thng, bao nhiu thng cha ti k hn v li sut khng k hn mi thng l bao nhiu ti thi im rt tin ? Bit rng gi tit kim c k hn th cui k hn mi c tnh li v gp vo vn tnh k hn sau, con nu rt tin trc k hn, th

li sut tnh tng thng v gp vo thng sau tnh thng sau. Nu s lc quy

trnh n phm trn my tnh gii.Bi 10 : ( 5 im )

Cho tam gic nhn ABC c ba gc nhn. Cnh BC = a (cm), = ( , = ( . K ng cao AH. Tnh di ng cao AH ? bit ( = 54eq \l(\o\ac(0, )) , ( = 55eq \l(\o\ac(0, )) , a = 1,787879 cm . ------------------ Ht ------------------_1346095943.unknown

_1346096604.unknown

_1346096939.unknown

_1346097219.unknown

_1346097640.unknown

_1471506749.unknown

_1471506748.unknown

_1346097608.unknown

_1346097085.unknown

_1346097157.unknown

_1346096973.unknown

_1346096688.unknown

_1346096742.unknown

_1346096671.unknown

_1346096087.unknown

_1346096529.unknown

_1346096011.unknown

_1346095369.unknown

_1346095640.unknown

_1346095792.unknown

_1346095589.unknown

_1346094809.unknown

_1346095117.unknown

_1346061866.unknown