Prove the identity 1 cos x sin x2 sin2xSolution1cos x si
Prove the identity 1 – (cos x – sin x)^2 = sin(2x)
Solution
1-(cos x - sin x)2= sin(2x)
starting with the left side
1-(cosx -sinx)2
1-(cos2x + sin2x - 2sinx cos x)
We have to use following identities
cos2x + sin2x = 1 and 2 sinx cosx=sin2x
And on using these identities we get
1-(1-sin2x) = 1-1+sin2x=sin2x which is equal to the right side
