Negative Exponent Rule

mathdad

Full Member
Joined
Apr 24, 2015
Messages
925
If a does not equal 0, and if n is a positive integer, the book goes on to define the following:

a^(-n) = 1/[a^(n)], if a is not 0.

Michael Sullivan makes this comment:

"Whenever you encounter a negative Exponent, think 'reciprocal.' "

Sample A

5^(-2) = 1/[5^(2)] = 1/25

Yes?

What about expressions?

Sample B

(x + 2)^(-2) = 1/[(x + 2)^2]

Can I leave the answer as 1/[(x + 2)^2]?

Must I simplify further?

(x + 2)^2 = (x + 2)(x + 2) = x^2 + + 4x + 4.

The answer then becomes 1/(x^2 + 4x + 4).

You say?
 
Top