# Partial fractions

1. Sep 19, 2012

### arl146

1. The problem statement, all variables and given/known data
determine the indefinite integral: ∫ (4x+10)/(9x^2+24x+16) dx

2. Relevant equations
partial fractions technique

3. The attempt at a solution

i know it's partial fractions and i thought i did it right but i got the wrong answer.

(4x+10)/(9x^2+24x+16) = (4x+10)/(3x+4)^2 = A/(3x+4) + B/(3x+4)^2
is that part right before I continue?

2. Sep 19, 2012

### Ray Vickson

Yes, that is the right idea.

RGV

3. Sep 19, 2012

### voko

Yes, that's right.

4. Sep 19, 2012

### HallsofIvy

Staff Emeritus
As others have told you that is correct. Now multiply both sides by (3x+4)^2 to get (4x+10)(3x+ 4)^2= A(3x+ 4)+ B. Taking x= -4/3 gives an easy solution for B. Take x to be any other number, say, x= 0, to get an equation for A.

5. Sep 19, 2012

### arl146

ohhhh .. i see what i did. ok .. so i was doing A(3x+ 4)^2 + B(3x+4) not realizing the denominator difference. stupid mistake. thanks!