4sina*cosa+sin(2a-П)=sina

Question

4sina*cosa+sin(2a-П)=sina

Answer 1

2sin 2a + sin 2a= sin a
3 sin 2 a - sin a = 0
sin a ( 6cos a - 1) = 0
sin a = 0
a= pk, k € Z.
6 cos a = 1
cos a= 1/6
a= ± arccos 1/6 + 2 pi l, l € Z.