- A2
- B4
- C3
- D1
Step-by-Step Solution
2coθ − 1 = cos θ → (2cos θ + 1)(cos θ − 1) = 0. cos θ = 1 gives 0°; cos θ = −1/2 gives 120° and 240°. That is 3 angles.
Answer: C) 3
How many angles θ with 0° ≤ θ < 360° satisfy cos 2θ = cos θ?
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