sin (x + 30) = cos (2x+30) ; 0 < x < 360

@
sin(x + 30) = cos (2x +30)
sin(x + 30) = sin { 90 - (2x + 30)}
sin(x+30) = sin (-2x + 60)
x+30 = -2x + 60  + k. 360
x + 2x = 30+60 + k. 360 
3x = 90 + k. 120
x = 30 + k.120  atau x = 150 +k. 360
k=0, x = 30, 150
k =1, x = 150, 510
x= {30, 150)