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Question: Use half-angle formula to find the value of tan 15°.


A ) 2 - 3
B ) 2 +3
C ) 233
D ) 36

Steps to derive

1 tan 15° = 1 - cos 30o sin 30o
 [Using :tan(x2) = 1 - cosxsinx; 15° = 12 · 30°.]

2 = 1-3212
 [cos 30° = 32; sin 30° = 12]

3 = 2 - 3



Hence the right answer is Option A

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