Question

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

Answer 1

Answer:

sin2A+cos2A+2sinA.cosA+sin2A+cos2A--2sinA.cosA

1+2sinA.cosA+1--2sinA.cosA

1+1=2

Answer 2

Answer:

Step-by-step explanation:

 $=sin^{2} A+2sinAcosA+cos^{2} +sin^{2} A-2sinAcosA+cos^{2}A\\=1+2sinAcosA+1-2sinAcosA\\=1+1\\=2$