Question

Which double-angle or half-angle identity would you use to verify that sin2x/2sin^2x=cotx

Answer 1

[D] sin 2x = 2 sin x cos x

Answer 2

Double-angle or half-angle identity used is

sin2x= 2 sinx cosx

Explanation:

We have to find
`(sin2x)/(2sin^2x)`

sin2x= 2 sinx cosx

Substituting

`(sin2x)/(2sin^2x)=(2sinxcosx)/(2sin^2x)=(cosx)/(sinx)=cotx`

Double-angle or half-angle identity used is

sin2x= 2 sinx cosx