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Question: Using half-angle formula, the value of sin 15° is:


A ) - 2 -32
B ) - 2 +32
C ) 2 +32
D ) 2 -32

Steps to derive

1 sin 15° = +1 â€“ cos30o2
 [Use sin x2 = +1 - cos x2
sin 15° is positive.
15° = 12. 30° ]

2 = 1 -322 =  2-34 = 2 -32
 [Use cos 30° = 32.]



Hence the right answer is Option D

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