Integral of.......

3(u+1)

u^2 +1 du

it started as the integral of...

3x

x^2-2x+2

and i completed the square to get the integral of...

3x

(x-1)^2 +1

Then put u = x-1, so that x = u+1, and thats how i got to where i am now... i always get stuck at this part...thanks