Question
Mathematics Question on Inverse Trigonometric Functions
Find the values of sin(3π−sin−1(−21)) is equal to
A
21
B
31
C
41
D
1
Answer
1
Explanation
Solution
Let sin−1(−21)=x
Then, sin x=−21=−sin6π=sin(−6π).
We know that the range of the principal value branch of sin-1=[-π/2,π/2].
sin-1(-1/2)=-π/6
therefore sin(π/3-sin1(-1/2))=sin(π/3+π/6)=sin(3π/6)=sin(π/2)=1.
The correct answer is D.