# Intergration problem

1. Feb 8, 2009

### miller8605

1. The problem statement, all variables and given/known data
i'm taking a defitinite integral from sqrt2 to 2 of the function 1/x^3*sqrt(x^2-1)dx.

2. Relevant equations

3. The attempt at a solution
I seperated it into 1/x^3 and 1/sqrt(x^2-1). I have the second part using trig sub. as being inverse sec(x/1) dx. I believe i did this part correctly.

What I can't remember is that I make 1/x^3 to x^-3 and then integrate it that way with the final being -1/2(1/x^2)??

2. Feb 8, 2009

### rootX

Why don't try the substitution u = x^2?