# Integration by Parts.

1. Oct 13, 2008

### nonechelon

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

1/(u²(a+bu)²) a and b are constants u is the variable

2. Relevant equations

3. The attempt at a solution
i know im suppose to use substition by parts but i dont know what to use.

2. Oct 13, 2008

### Staff: Mentor

I'm confused. The title says "Integration by parts". Later on, you said you supposed to use "substitution by parts" which is not a technique I've ever heard of. There's a technique called "substitution".

There's also a technique called "partial fractions" or "partial fraction decomposition" in which you can decompose a complicated rational expression into a sum of simpler rational expressions.

So how are you supposed to do this problem?

3. Oct 13, 2008

### nonechelon

oops i mean integration by parts i dont know why i said substitution.sorry

4. Oct 13, 2008

### Defennder

The best approach would be to decompose the fraction first into it's partial fractions as suggested by Mark44. Then integrate the partial fractions separately.