2tan3x.cos2x+1=tan3x+2cos^2x (x is greater than 90 degree and less than 180 degree)

Dear Student,

2tan3x cos2x + 1 = tan3x + 2cos2x
Or ,2tan3x cos2x + 1 - tan3x - cos2x= 0
Or, tan3x ( cos2x - 1) - ( cos2x- 1) = 0
Or , (tan3x-1) (cos2x-1) =0
Either, tan3x-1=0. Or, cos2x= 1
Or, tan3x = 1. Or, 2x= (4n+1)π/4
Or, 3x = nπ •°• x= (4n+1)π/12
•°• x = nπ/3

Regards