Question

State whether the following are true or false. Justify your answer. 

sin (A + B) = sin A + sin B

Answer 1

False. ∵ A = 60°, B = 30° 

LHS = sin (A + B) = sin(60 + 30) = sin 90° = 1 

RHS = sin A + Sin B = sin 60° + sin 30° 

= \(\frac{\sqrt 3}{2}\) + \(\frac{1}{2}\) ≠ 1 

∴ LHS ≠ RHS.