Solve 2 sin x = 1 for 0° ≤ x ≤ 360°.
Answer and explanation
Correct answer: A. x = 30° and x = 150°
- Step 1: sin x = 1/2, so the reference angle is 30°. Step 2. Sine is positive in quadrants I and II: 30° and 180° − 30° = 150°. Answer: 30° and 150°. Why not the others: 330° is in a quadrant where sine is negative, 60 and 120 belong to sin x = √3/2 and the last misses the second quadrant.
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