Q.

Considering the principal values of the inverse trigonometric functions, sin1(32x+121x2), 12<x<12, is equal to          [2025]

1 5π6sin1x  
2 π4+sin1x  
3 5π6sin1x  
4 π6+sin1x  

Ans.

(4)

Let sin1x=θ,π4<θ<π4

 x=sinθ

Now, sin1(32x+121x2)

=sin1(sinθ cosπ6+cosθ sinπ6)

=sin1(sin(θ+π6))=θ+π6=sin1x+π6