integral 8/((4x^2+1)^2) dx
I know you have to let x=1/2tanu
therefore dx = 1/2 sec^2 u du
But I get a wrong answer! Somewhere along the way I get messed up.
Also:
integral e^t/(sqrt(e^(2t)+9)) dt from 0 to ln4
Use a substitution like u=e^t to simplify the problem, then let u = 3tant
and so du = 3sec^2t
I also get a wrong answer for this one. Be careful with the limits.