Question

What is the integral of `int tan (5x)dx`?

Answer 1

`-1/5log_e(cos(5x))`

Explanation:

`tan(5x) = sin(5x)/(cos(5x)) =( -1/5(dcos(5x))/(dx))/cos(5x)`

then

`int tan(5x)dx = int ( -1/5(dcos(5x))/(dx))/cos(5x)dx = -1/5log_e(cos(5x))`