Upload
nikita-sharma
View
403
Download
28
Tags:
Embed Size (px)
DESCRIPTION
exponent and powers
Citation preview
EXPONENTS AND POWERS
TEAM: SUCCESS
INTRODUCTION
WHAT IS EXPONENTS ?
The exponent of a number says how many times to use that number in a multiplication.
It is written as a small number to the right and above the base number.
In this example: 82 = 8 × 8 = 64(The exponent "2" says to use the 8 two times in a multiplication.) Exponents are also called Powers or Indices
What if the Exponent is 1, or 0?
1 If the exponent is 1, then you just have the number itself (example 91 = 9)
0 If the exponent is 0, then you get 1 (example 90 = 1)Example: Powers of 5
52 1 × 5 × 5 25
51 1 × 5 5
50 1 1
5-1 1 ÷ 5 0.2
5-2 1 ÷ 5 ÷ 5 0.04
If you look at that table, you will see that positive, zero or negative exponents are really part of the same (fairly simple) pattern
LAWS OF EXPONENTS WITH EXAMPLES32 × 33 = 32 + 3 = 35 = 243
36/32 = 36 – 2 = 34 = 81
If a is any number except 0, then a0 = 1.
93/93 = 93 – 3 = 90 = 1
(22)3 = (2)2 × 3 = 2 6 = 64
(10)5 = (2 × 5)5 = 25 × 55
POWERS WITH NEGATIVE EXPONENTS
Negative ExponentsA NEGATIVE EXPONENT MEANS HOW MANY TIMES TO DIVIDE BY THE NUMBER.
Example: 8-1 = 1 ÷ 8 = 1/8 = 0.125Or many divides:
Example: 5-3 = 1 ÷ 5 ÷ 5 ÷ 5 = 0.008But that can be done an easier way:
5-3 could also be calculated like:1 ÷ (5 × 5 × 5) = 1/53 = 1/125 = 0.008
Use of exponents to express small no. in standard form
ANSWER THE FOLLOWING QUESTIONS :
Q 1. The value of 25 is _________ .(a)3 (b) 10 (c) 32 (d) 7
ans. c
In standard form 21600000 is written as • 2.16 × 107 (b) 216 × 107 (c) 2.16 × 105 (d) 216 × 100000
ans.a. Charge of an electron is 0.000,000,000,000,000,000,16 coulomb and in exponential form it can be written as• 16 × 10-18 coulomb (b) 1.6 × 10-21 coulomb (c) 1.6 × 10-19 coulomb (d) 16 × 10-21 coulomb
ans.c
MADE BY :GROUP:SUCCESSGROUPMEMBER: NIKITA,SALONI,VAIBHAV,VISHESH