1. The problem statement, all variables and given/known data I need to find the derivative of x / (2 - tan x). 2. Relevant equations I do everything Wolfram Alpha does here: http://www.wolframalpha.com/input/?i=derivative+x+/+(2+-+tan+x) Except I don't understand why the answer is (2+x sec^2(x)-tan(x))/(-2+tan(x))^2. I get (x sec^2 x) / (2 - tan x). 3. The attempt at a solution The solution above. Again just what Wolfram Alpha does, but I simplify: (2+x sec^2(x)-tan(x))/(tan(x) - 2)^2 to (x sec^2 x) / (2 - tan x).