Trigonometryhard · Past Paper
In triangle ABC, tan A/2 tan B/2 + tan B/2 tan C/2 + tan C/2 tan A/2 = ?
A1
B0
C-1
Dtan A/2 tan B/2 tan C/2
✓ Correct Answer: A — 1
A standard conditional identity for the half-angles of any triangle.
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