Trigonometrymedium · Past Paper
If cos θ = 1/2, find the value of (1 - 2 sin²θ).
A1/2
B-1/2
C0
D1
✓ Correct Answer: B — -1/2
If cos θ = 1/2, θ = 60°. sin 60° = √3/2. 1 - 2(√3/2)² = 1 - 2(3/4) = 1 - 1.5 = -0.5.
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✓ Correct Answer: B — -1/2
If cos θ = 1/2, θ = 60°. sin 60° = √3/2. 1 - 2(√3/2)² = 1 - 2(3/4) = 1 - 1.5 = -0.5.
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