Derivatives of sin x, cos x, tan x, e^x and ln x | Derivatives of common functions | Khan Academy
Learn the derivatives of several common functions. ... tan(2x) - cot(2x) = sin(2x)/cos(2x) - (cos(2x)/sin(2x)) Find and use a common denominator: = [sin^2(2x) - cos^2(2x)] / sin(2x)cos(2x) Remember that `cos(2a) = cos^2(a) - sin^2(a)`...