question_answer

The number of real solutions of the equation\[\sqrt{1+\cos 2x}=\sqrt{2}{{\sin }^{-1}}(sinx),-\pi \le x\le \pi \] is

A) 0                     

B) 1

C) 2                     

D) infinite

Correct Answer: C

Solution :

[c] Here \[\left| \cos x \right|={{\sin }^{-1}}(sinx)\] From the graph, the number of solutions is 2.