Question

is 1- cos2theta= 2sin^2theta an identity

Answer 1

Answer:

Yes, it is an identity. $sin^{2}$∅ + $cos^{2}$∅ = 1

Step-by-step explanation:

on bringing $cos^{2}$∅ to RHS, it changes to negative and it becomes

$sin^{2}$∅ = 1 -  $cos^{2}$∅

Answer 2

Step-by-step explanation:

Yes it is an identity.

It is the formula for cos2theta.

cos2theta = 1-2sin²2theta