Question

What is the Integral of `sec^2(x) * tan^2(x)`?

Answer 1

`1/3tan^3x+C`.

Explanation:

Suppose that, `I=intsec^2xtan^2xdx`.

If we subst. `tanx=y," then, "sec^2xdx=dy`.

`:. I=inty^2dy=y^3/3=1/3tan^3x+C`.