# Homework Help: Evaluate Integral

1. Jan 13, 2010

### danielatha4

1. The problem statement, all variables and given/known data
$$\int$$$$\frac{4}{x^2-1}$$

2. Relevant equations

3. The attempt at a solution
I thought I had this right...

$$\frac{4}{x^2-1}$$ = 2 ($$\frac{1}{x-1}$$-$$\frac{1}{x+1}$$)

therefore,

$$\int$$$$\frac{4}{x^2-1}$$=2(ln(x-1)-ln(x+1))

I then have to evaluate from 2 to 3 and I get .814, but it isn't right.

Last edited: Jan 13, 2010
2. Jan 13, 2010

### danielatha4

Nevermind, I believe I figured it out.

Edit: Okay, I don't understand where I went wrong. Any help please?

Last edited: Jan 13, 2010
3. Jan 13, 2010

### Bohrok

I get log(9/4) ≈ 0.81093
Perhaps you entered it wrong in a calculator?

4. Jan 13, 2010

### danielatha4

Oh gees... rounding error... thanks