3.5 DERIVATIVES OF TRIG FUNCTIONS. Some needed trig identities:. Trig Derivatives. Graph y 1 = sin x and y 2 = nderiv (sin x) What do you notice?. Proof Algebraically. (use trig identity for sin(x + h) ). Proof Algebraically. 0. 1. Trig Derivatives.
(use trig identity for sin(x + h))
(use trig identity for cos(x + h))
(trig id cos2x + sin2x = 1)
f(x) = sec x at the point