We also know that when 81 is written as 34 , it is said to be in exponential form. The number '4' is the 'exponent' or 'index' and 3 is the 'base'. we read it as " 81 is the 4th power of base 3".

Rec Recall the laws of exponents

If a, b are real numbers, where a ¹ 0, b ¹ 0 and m, n are integers,then

(i) am.an=am+n (ii) (abm)=am.bm (iii) (a/b)m=am/bm

(iv) (am)n=amn

(v) a0=1 (iv) a-m=1/am

Do - This

1. Evaluate

(i)21 (ii) (4.73)0 (iii) 03 (iv) (–1)4 (v) (0.25)-1 (vi) (5/4)2 (v) 1*1/42

2. (a) Express 10, 100, 1000, 10000, 100000 is exponential form

(b) Express in simplest exponential form

(i) 16+64 (ii) 25 * 125 (iii) 128 / 32


EXPONENTIAL AND Logarithims

Let us Observe the following

2x = 4 = 22 gives x = 2

3y = 81 = 34 gives y = 4

10z = 100000 = 105 gives z = 5

can we find the value of x fot the following?

   2x=5,    3x=7,    10x=5

If so,what are the values of x?

For 2x=5,What should be the power to which 2must be raised to get 5?

Therefore, we need to establish a new relation between x and 5




page no:18

Home