SOLUTION: verify that the given equation is an identity: tan2x = 2cotx/cot^2 x - 1

Algebra ->  Trigonometry-basics -> SOLUTION: verify that the given equation is an identity: tan2x = 2cotx/cot^2 x - 1      Log On


   

Question 275502: verify that the given equation is an identity:
tan2x = 2cotx/cot^2 x - 1
Answer by Greenfinch(383) About Me  (Show Source):
You can put this solution on YOUR website!
tan 2x = sin 2x/cos 2x=( 2 sin x cos x)/(cos^2 x- sin^2 x) Divide by sin^2 x
=( 2 cos x/ sin x)/(cos^2x/sin^2 x) - (sin^2 x / sin^2 x)
= 2 cot x/ (cot^2 x - 1)