Answer:
x = 0, π, 7π/6, 11π/6
Step-by-step explanation:
cos(2x) = sin x + 1
Use double angle formula.
1 − 2 sin²x = sin x + 1
Move everything to one side.
0 = 2 sin²x + sin x
Factor.
0 = sin x (2 sin x + 1)
Solve.
sin x = 0 or -½
x = 0, π, 7π/6, 11π/6
