1. Sep 12, 2011

### roger12

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

Simplify the following, giving the result without fractional indices:

[(x^2 -1)^2 * √(x+1)]/ (x-1)^3/2

2. Relevant equations
3. The attempt at a solution

There are no common bases to add the indices and no common indices to multiply out the bases so I tried this and got it wrong, please show me where though:

[(x-1) (x+1)]^2 * (x+1)^(1/2)] / (x-1)^(3/2)

=[(x-1)^2 * (x+1)^2 * (x+1)^(1/2)] / (x-1)^(3/2)

multiplied the indices by 2 and got rid of the fractions

=[(x-1)^4 * (x+1)^4 * (x+1)] / (x-1)^3

= (x-1) *(x+1)^5

But my textbook says it is :( x + 1 )^2 √( x^2 - 1 )

Thank You.

2. Sep 12, 2011

### lewando

You effectively squared the original problem. Now you need to un-square your result.

3. Sep 13, 2011

### HallsofIvy

Staff Emeritus
"Without fractional indices" just mean you need to use the square root:
$$(x- 1)^{3/2}= \sqrt{(x-1)^3}$$

4. Sep 14, 2011

### roger12

Thank You, Everyone.