Question

Integral Question:
Int(tan(3x)^2*sec(3x)^2 dx
please show full steps

Answer 1

use wolframalpha it can show steps

Answer 2

http://www.wolframalpha.com/input/?i=Int%28tan%283x%29%5E2*sec%283x%29%5E2+dx+

Answer 3

theres some parts of wolfram alpha that do it in a weird way

Answer 4

which step do u not understand there?

Answer 5

\[u = \tan(3x) \Rightarrow du = 3\sec^2(3x)dx\] \[\Rightarrow I = \int \tan^2(3x)\sec^2x(3x) = \frac{1}{3}\int u^2 du = \frac{u^3}{9}+K = \frac{\tan^3(3x)}{9} + K.\]