Trigonometrymedium · Past Paper
What is 1 - 2 sin^2(22.5) equal to?
A1/2
B1/sqrt(2)
Csqrt(3)/2
D1
✓ Correct Answer: B — 1/sqrt(2)
cos(2 * 22.5) = cos(45) = 1/sqrt(2).
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