# Thread: Integration with partial fractions

1. ## Integration with partial fractions

hi - I've got some revision questions ready for my easter exams and I'm having issues with this one:

Find the values of A,B & C

2 + 3x / ( ( 1+ x )^2)(4 + 3x) = A/(1 +x) + B/(1+x)^2 + C/(4 + 3x)

Pretty simple stuff an I get A = 6 , B = -1 & C = -18

It then asks to integrate the function with in the limits of 4 & 3 and show that it is equal to:

6ln(35/32) - 3/10

but I get 6ln(65/64) - 1/20

I can't see if I'm wrong or if the question is wrong... I know what is more probable so any advice would be grateful

Thanks, D

2. Originally Posted by dojo
hi - I've got some revision questions ready for my easter exams and I'm having issues with this one:

Find the values of A,B & C

2 + 3x / ( ( 1+ x )^2)(4 + 3x) = A/(1 +x) + B/(1+x)^2 + C/(4 + 3x)

Pretty simple stuff an I get A = 6 , B = -1 & C = -18

It then asks to integrate the function with in the limits of 4 & 3 and show that it is equal to:

6ln(35/32) - 3/10

but I get 6ln(65/64) - 1/20

I can't see if I'm wrong or if the question is wrong... I know what is more probable so any advice would be grateful

Thanks, D
my TI-89 agrees with your solution if the original definite integral is

$\int_3^4 \frac{2+3x}{(1+x)^2 (4+3x)} \, dx$

3. Thanks - I'll bring it up with my Calculus teacher tomorrow.