Question

prove that 4sinA.cosA.cos2A =sin4A​

Answer 1

Answer:

4sinA.cosA.cos2A =sin4A​

LHS:

4 sin A. cos A . cos 2A

2sinA cos A 2cos2A

Remember: 2 sin A cos A = sin 2A

2sin 2A cos 2A

Sin 4A = RHS

LHS = RHS

Hence, proved.