I dont know why, the solution of this integral is diffrent from my book.
Can u tell me why it is incorrect.
If thats meant to be tanh x rewrite like this:
$\displaystyle int (tanh^2 x) dx = int (1-sech^2 x) dx$
as $\displaystyle cosh^2 x - sinh^2 x = 1$ divide through by $\displaystyle cosh^2 x$
so you then have:
$\displaystyle x - tanhx + c$
Is that what the answer is meant to be?