Identity sec2x = tan2x 1 Hence, ∫(tanx)2dx = ∫tan2xdx = ∫(sec2x −1)dx = ∫sec2xdx −∫1dx = tanx − x C Enjoy Maths!$\sin(x)$ and $\cos(x)$ This is since any trigonometric function (that I know of so far) can be written with the basic $\sin(xI had a calculus final yesterday, and in a question we had to find a primitive of $\tan(x)$ in order to solve a differential equation A friend of mine forgot that such a primitive could easily be found, tried to integrate $\tan(x)$ by parts and then arrived to the result $0 = 1$
What Is The Integration Of Tan 2x Solution Quora