Question

Sin2a+sin2b -sin2c=-4sina sin
b sinc

Answer 1

Answer:

= 4 sin A. sin B.sin C

Step-by-step explanation:

sin 2A + sin 2B + sin 2C = 2 sin C. cos (A – B) + 2 sin C. cos C = 2 sin C (cos(A – B) + cos C] = 2 sin C[cos (A – B) + cos {180 – (A + B)}] = 2 sin C[cos (A – B) – cos (A + B)]

= 2 sin C[-2 sin A . sin(- B)] = 4 sin A. sin B.sin C