1. The problem statement, all variables and given/known data show that ((tanx - sinx)/sin^3x) = (1/(cosx - cos^2x)) 2. Relevant equations sin^2 = 1-cos^2v cos^2 = 1-sin^2v 3. The attempt at a solution On the left hand side: I plugged in sinx/cosx for tanx. I then divided both the numerator and denominator by sinx to get ((1/cosx - 1)/ sin^2x). After this point I got stuck. I tried plugging in 1-cos^2x for sin^2x and simplifying the fraction, but it didn´t work. Do you guys have any tips on how to progress?