Hi, how do I integrate this?
Int 1/(1 + cos 2x) dx
Thanks
What he's up to is
$\displaystyle \int \frac{dx}{1 + cos(2x)} = \int \frac{dx}{1 + 2cos^2(x) - 1} = \int \frac{dx}{2cos^2(x)}$
$\displaystyle = \frac{1}{2} \int sec^2(x) dx$
Do you know of any function who's derivative is $\displaystyle sec^2(x)$?
-Dan
Edit: Jhevon politely and quietly PMed me that I had made a mistake and left a "2" out. I have fixed this mistake.