Derivatives of sin x, cos x, tan x, e^x and ln x | Product and quotient rules | Khan Academy
Here is a proof of the derivative of sin x. d/dx (sin x) = lim h→ 0 (1/h) [sin(x+h) - sin (x) ] _by definition of derivative_. _Using the angle sum identity: sin(x+h) = sin(h) cos(x) + cos(h) sin(x)_ d/dx(sin x) = lim h→ 0 (1/h) { sin(h) cos(x)+cos(h) sin...