Prove the following Identity:- sin4A + cos4A = 1 - 2 sin2A cos2A Share with your friends Share 3 S. Usha Rani answered this sin4A+cos4A=(sin2A)2+(cos2A)2=(sin2A+cos2A)2- 2 sin2A cos2A (because a2+b2=(a+b)2-2ab)=12-2 sin2A cos2A ( because sin2A+cos2A=1)=1-2 sin2A cos2A 37 View Full Answer Stunning Dude....... answered this sin4a + cos4a(sin2a)2 + (cos2)2(sin2a + cos2a)2 - 2sin2acos2a(1)2 - 2sin2acos2a1 - 2sin2acosa = RHS 3
