# Partial fraction problem

1. Sep 16, 2012

### charmedbeauty

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

Find ∫18/((x2+9)(x-3))

2. Relevant equations

3. The attempt at a solution

Im a little stuck on this.

18∫1/((x2+9)(x-3))

Im not sure how to turn this into a partial fraction.. help.

Thanks

2. Sep 16, 2012

### Simon Bridge

3. Sep 16, 2012

### Curious3141

The general form for the PF decomposition would be:

$$\frac { 18 }{ (x^{ 2 }+9)(x-3) } =\frac { Ax+B }{ x^{ 2 }+9 } +\frac { C }{ x-3 }$$

First find C by using the Heaviside coverup rule (put x = 3 after multiplying both sides by (x-3).

Then just subtract the $\frac { C }{ x-3 }$ from the LHS and simplify to find the remaining term.

4. Sep 16, 2012

### charmedbeauty

ok yeah I figured it out thanks.