Verify this is an identity? cos2x/sin²x=csc² x-2

1 Answer
Apr 3, 2018

Verified below

Explanation:

Using
cos2x= 1-2sin^2x
1/sinx= cscx

Start:
(cos2x)/(sin²x)=csc² x-2

(1-2sin^2x)/(sin²x)=csc² x-2

1/sin^2x-(2sin^2x)/sin^2x=csc² x-2

csc^2x-2=csc² x-2