# Thread: Incredibly simple indices sum

1. ## Incredibly simple indices sum

Can someone please use that math editor thing and change my post to write this equation down?

4 to the power of 3/2 * 2 to the power of negative 1/2

Anyway, thats the sum. My answer works out to 8 * 0.707 = 5.657, but in the math workbook the answer is 2. What am I doing wrong?

2. Originally Posted by yorkey
Can someone please use that math editor thing and change my post to write this equation down?

4 to the power of 3/2 * 2 to the power of negative 1/2

Anyway, thats the sum. My answer works out to 8 * 0.707 = 5.657, but in the math workbook the answer is 2. What am I doing wrong?
1. Your term is a product and not a sum:

$4^{\frac32} \cdot 2^{-\frac12}$

2. Are you sure that you have posted the question correctly? If yes then your approximate result is correct. The exact value is $\sqrt{32}$.

3. So my answer was correct then. $\sqrt{32}$ = 5.657.

Must be a typo in the book, because the way you wrote it out is exactly as it is in the book. Thanks!

4. Hi Yorkey

I also have problems with exponents. This video is good: http://www.mathplanet.com/education/...s-of-exponents

I use this forum to ask questions and watch videos on http://www.mathplanet.com

This forun rocks!!!!

5. Originally Posted by earboth
1. Your term is a product and not a sum:

$4^{\frac32} \cdot 2^{-\frac12}$

2. Are you sure that you have posted the question correctly? If yes then your approximate result is correct. The exact value is $\sqrt{32}$.
$\sqrt{32}$ would be better written as $4\sqrt{2}$.

6. Originally Posted by yorkey
4 to the power of 3/2 * 2 to the power of negative 1/2
.......but in the math workbook the answer is 2.
IF answer is 2, then expression should be:
2^(3/2) * 2^(-1/2)