Solving Improper Integral: \int \frac{dx}{(ax+b)^2}

[suspenc3]

Hi, for some reason I can't remember and I've been looking everywhere for some info but can't find anything. I am trying to find out the answer to :

$$\int_1^i^n^f^i^n^i^t^e \frac{1}{(3x+1)^2}dx$$

what is the integral of $$\int \frac{dx}{(ax+b)^2}$$?

Thanks

 

[StatusX]

Try the substitution u=ax+b.

 

[suspenc3]

ahhh, got it, THanks