1. ## Calculus - Integration

When you integrate 2sin$\displaystyle x$cos$\displaystyle x$$\displaystyle /1-2\displaystyle (cosx)^2is the answer \displaystyle -$$\displaystyle (sec2x)^2$/2?

If not, then what would be the proper approach?

2. What about substituting $\displaystyle u=1-2cos^{2}(x)$ and trying to answer your question by yourself?

3. I get 1/2ln(1-2cos^2x)+c. Is that right?

4. Originally Posted by bhuang
I get 1/2ln(1-2cos^2x)+c. Is that right?
Does it work when you differentiate it?