Question

sin 4a-sin 2a=cos 3a find value of a​

Answer 1

Answer:

using SinC-SinD-

2[Cos(4a+2a)/2]Sin(4a-2a)/2=Cos3a

2Cos3aSina=Cos3a

2Cos3aSina-Cos3a=O

Cos3a[2Sina-1]=0

on comparing-

Cos3a=0

Cos3a=Cos0°

3a=2nπ±0

a=2nπ/3

or-2Sina-1=0

Sina=1/2

Sina=Sinπ/6

a=nπ+(-1)^nπ/6