Answer:
x = π/2, 7π/6, or 11π/6
Step-by-step explanation:
sin² x − cos² x − sin x = 0
Use Pythagorean identity to write cosine in terms of sine.
sin² x − (1 − sin² x) − sin x = 0
sin² x − 1 + sin² x − sin x = 0
2 sin² x − sin x − 1 = 0
Factor:
(2 sin x + 1) (sin x − 1) = 0
Solve:
sin x = -1/2 or 1
x = π/2, 7π/6, or 11π/6
