- #1
jdawg
- 367
- 2
Homework Statement
∫(x2+9x)/(4x2) dx
Homework Equations
The Attempt at a Solution
I started by using trigonometric substitution:
x2=9tan2θ
x=3tanθ
dx=3sec2θ dθ
∫9(sec2θ)/4(9tan2)*3sec2θ dθ
(3/4)∫(sec4θ)/(tan2θ) dθ
I'm not really sure what to do next, or if I even used the best method of integration. Could I maybe use u substitution and let tanθ=u? Or maybe rewrite the integral as (1/cos4θ)/(sin2θ/cos2θ)
Please help! Also if you have any tips on how to spot which integration techniques to use that would be great!