Trigonometrymedium · Past Paper
If A + B = 45, then (1 + tan A)(1 + tan B) = ?
A1
B2
C3
D4
✓ Correct Answer: B — 2
1 + tan A + tan B + tan A tan B = 1 + tan(A+B)(1 - tan A tan B) + tan A tan B = 1 + 1(1 - tan A tan B) + tan A tan B = 2.
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