1. 2cos I -2x + 43 cos4x = 4 cos x-1

2. 4 sin + cos +3= 4cos cos )

3. 2cos2x+3cosx=2cos3x= 4sinx sin 2x


4. 2+ 3(sin 2x-3sin x = cos 2x+3cosx

5. 2cos^x+2/3 sin x cosx+1=3(sin x+ V3 cos x)​