Trigonometrymedium · Past Paper
What is cos(2A) in terms of cos A?
A2 cos^2 A - 1
B1 - 2 cos^2 A
C2 cos A
Dcos^2 A - 1
✓ Correct Answer: A — 2 cos^2 A - 1
Standard double angle formula for cosine.
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✓ Correct Answer: A — 2 cos^2 A - 1
Standard double angle formula for cosine.
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