Use the double angle identities to derive sin^2(x) in terms of linear powers of common trig functions. Prove the identity: cotx=(sin2x)/(1-cos2x)

Question

the first step is very unclear and confusing for me so im not sure how to start

Answer 1

sin2x / (1-cos2x) = 2sinxcosx / (1 - (1-2sin²x)

 

                          = 2sinxcosx / (2sin²x)

 

                          = cosx / sinx = cotx