Partial fractions and integral

[nameVoid]

Homework Statement

I((3x^2+x+4)/(x^4+3x^2+2),x)
I((3x^2+x+4)/((x^2+1)(x^2+2)),x)
I(3x^2/((x^2+1)(x^2+2)),x)+I((x+4)/((x^2+1)(x^2+2)),x)
from here i have used partial fractions with no luck

Homework Equations

The Attempt at a Solution

 

[Gib Z]

It is probably easier to use partial fractions right after you get to:

$$\int \frac{ 3x^2 + x+4}{(x^2+1)(x^2+2)} dx$$.

Please show us your working so we can tell you where you went wrong.

 

[HallsofIvy]

$$\frac{ 3x^2 + x+4}{(x^2+1)(x^2+2)}= \frac{Ax+ B}{x^2+ 1}+ \frac{Cx+ D}{x^2+ 2}$$
Now, what did you do to try to find A, B, C, and D?