Question

i) Express the following as sum or difference of two trigonometric ratios
a) 12 Sin 3x. cos 2x​

Answer 1

Answer:

Using compound angle formula,2sinAcosB=sin(A+B)+sin(A−B)

2sinθcos2θ

=sin(θ+2θ)+sin(θ−2θ)

=sin(3θ)+sin(−θ)

=sin3θ−sinθ