∫ (x^2)/ [square root (x^2 +20)] dx
this is another problem assigned in my homework and im just really confused on what to do.. on how to use both.. help appreciated!
I think you intended . That is, the tangent is not squared.
That way
and
The integral becomes
which, switching to sine and cosine, becomes
Since that has an odd power of cosine, I would suggest multiplying both numerator and denominator by , and then letting so that .
a rational integral that can by done by "partial fractions".