Question

int. tan^4(x)dx

Answer 1

\[\int\limits_{}^{} \tan ^{4}xdx\]

Answer 2

First remember that 1 + tan^2 x = sec^2 x

Hence
\[ \tan^4 x = \tan^2 x (\sec^2 x - 1) \]

Now ... expand that ... and can you see how to integrate each term?

Answer 3

Remember also that
\[ \frac{d \ }{dx} \tan x = \sec^2 x \]

Answer 4

got it
thanks