Question

plz give me solution with explanation​

Answer 1

Answer:

3(1+cos2A)=1-cos2A

3+3cos2A=1-COS2A

3COS2A+COS2A=1-3

4COS2A=-2

COS2A=-2/4=-1/2

COS2A =COS(π-π/3)=COS (2π\3)

2A=2nπ+-(2π\3)

A=nπ+-(π/3) =4option

we take theta=A

COSX=COSY

X=2nπ+-(y,) we used this formula.