CBSE Class 12 Math 2011 Solved Paper

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Question : 2 of 29
 
Marks: +1, -0
Write the value of sin[π3−sin−1(−12)]
Solution:
sin[π3−sin−1(−12)]
Let sin−1(−12) = x
⇒ (−12) = sin x
⇒ sin x = - sin π6 = sin (−π6) = sin (2π−π6)
⇒ x = 2π - π6
∴ sin [π3−sin−1(−12)] = sin [π3−(2π−π6)]
= sin [−9π6]
= - sin [3Ï€2]
= - sin [Ï€+Ï€2]
= - [−sinπ2]
= + sin π2
= 1
Thus,sin[π3−sin−1(−12)] = 1
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