Question

Prove that : ( sin A + cos A )2 + ( sin A – cos A )2 = 2

Answer 1

Answer:

L.H.S= (sin A + cos A )^2+ (sin A - cos A )^2

       = sin² A + 2sinA.cosA + cos² A + sin² A - 2sinA.cosA + cos² A

       = sin² A + cos² A + sin² A + cos² A

       = 1 + 1

       = 2

       = R.H.S proved

Step-by-step explanation: