1. The problem statement, all variables and given/known data I came across a question like this on a test today, and it says it would be helpful to simplify before differentiation. However, I could not find ways to simplify (1- cos(x))/(1+cos(x)). 2. Relevant equations ln((1- cos (x))/(1+cos(x)))^7) 3. The attempt at a solution I have tried to multiply by the conjugate of denominator and got (1+2cos(x)+cos(x)^2)/sin(x)^2 But I still do not see how to tackle this problem.