Question

If A = 30°; show that:
(i) sin 3 A
= 4 sin A sin (60° - A) sin (60° + A)​

Answer 1

Answer:

taking rhs first sin 3×30 =sin90 =1 now take l.h.s then you get 4× sin30×sin(60-30) sin90 = 4×1/2×1/2×1 which is also equal to 1 hence LHS and RHS is equal or you can apply sin 3a formula.