Here is the question:
I have been trying so long and I still cannot seem to get it.
Any help is appreciated.
See here: - Wolfram|Alpha
Be sure to click on Show steps.
If you recall the identity $\displaystyle tan^2\theta + sec^2\theta = 1$ More so
In this case let $\displaystyle x = 5 tan\theta$ and $\displaystyle dx = 5sec^2\theta$
can you take it from here? Also with definite integrals remember to change your limits of integration properly