Trigonometryhard · Past Paper
Value of tan 20 tan 40 tan 80 is:
Asqrt(3)
B1
C3
D1/sqrt(3)
✓ Correct Answer: A — sqrt(3)
This follows the identity tan theta * tan(60-theta) * tan(60+theta) = tan 3theta = tan 60 = sqrt(3).
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