# Help with integration, involving integration by partial fractions.

1. Feb 25, 2009

### NCyellow

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

(3x^2-4)/(x^3-4x-6)

2. Relevant equations

I guess integration by parts... But how do i set this up?

3. The attempt at a solution

The numerator is exponentially lower than the denominator, so no long division.
The denominator seems not to factor out into anything... I tried doing a perfect squares situation, by factoring x out of the first two terms, but to no avail... Am I doing something wrong?

2. Feb 25, 2009

### Dick

Try a u substitution u=x^3-4*x-6. Numerator look familiar?

Last edited: Feb 25, 2009
3. Feb 25, 2009

### NCyellow

Wow, i'm an idiot... hahaha... Too busy trying my new integration skills and forgot substitution.

4. Feb 26, 2009

### Staff: Mentor

Substitution is one of the first techniques you learn, and is one of the simplest to use. So that should be one that you think about using first. Even if it's not applicable, you haven't wasted that much time.