# negative exponents

• Apr 7th 2008, 04:42 PM
Jerry Cunningham
negative exponents
Need some help again.

-2^-3 = ?

The answer in the book is -9/8

I thought it would be -1/8.

Jerry
• Apr 7th 2008, 04:48 PM
topher0805
$-2^{-3}$

$= -\frac {1}{2^3}$

$= -\frac {1}{8}$

The book is wrong.
• Apr 7th 2008, 05:01 PM
Mathstud28
Here you go
Quote:

Originally Posted by Jerry Cunningham
Need some help again.

-2^-3 = ?

The answer in the book is -9/8

I thought it would be -1/8.

$a^{-b}=\frac{1}{a^{b}}$...therefore in this case since it is $-2^{-3}=\frac{1}{-2^3}=\frac{1}{-8}=\frac{-1}{8}$