Trigonometryhard · Past Paper
Value of tan 22.5° is:
A√2 - 1
B√2 + 1
C1 - √2
D√3 - 1
✓ Correct Answer: A — √2 - 1
Using tan(θ/2) = (1 - cos θ) / sin θ, for θ=45: (1 - 1/√2) / (1/√2) = √2 - 1.
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