Question

Evaluate $\frac{3cosA - 2cos 4A}{sin3A + 2sin4A}$, when A = 150°

Preferably using double and triple angle formula
(ie sin 2A = 2sinAcosA)
(sin 3A = 3sinA - 4tan^3A, etc)

Answer 1

the formula of sin3A is wrong....it is sin3A =3sinA -4sin^3 A