# Easy exponential question-> 1/3(8)^(-2/3)

1. Nov 13, 2012

### nukeman

Easy exponential question---> 1/3(8)^(-2/3)

1. The problem statement, all variables and given/known data

I am doing a linear approximation question, and got stuck here with this simple stuff.

1/3(8)^(-2/3)

Can anyone explain what I need to do to turn the above into 1/12 ?

2. Relevant equations

3. The attempt at a solution

2. Nov 13, 2012

### BloodyFrozen

Re: Easy exponential question---> 1/3(8)^(-2/3)

$$8^{\frac{-2}{3}} = \frac{1}{8^{\frac{2}{3}}}$$

3. Nov 13, 2012

### Ray Vickson

Re: Easy exponential question---> 1/3(8)^(-2/3)

What you have written reads as
$$\frac{1}{3} 8^{-2/3}.$$ Is that what you meant, or did you want
$$\frac{1}{3\, 8^{-2/3}}?$$
If you mean the first one you should use brackets, like this: (1/3) 8^(-2/3), but if you mean the second one you should write 1/(8 2^(-2/3)).

RGV

4. Nov 14, 2012

### HallsofIvy

Staff Emeritus
Re: Easy exponential question---> 1/3(8)^(-2/3)

As BloodyFrozen said, 8-2/3= 1/82/3. Further, since 23= 8, 81/3= 2 and so 82/3= 22= 4.