Question

If $x\in [0,1]$ then the number of solution(s) of the equation $2\left[{\cos }^{-1}x\right]+6[\mathrm{sgn}(\sin x)]=3$ is/are
[Note: $[k]$ denotes greatest integer less than or equal to $k$ and $\mathrm{sgn}(x)$ denotes signum function of $x$.]

• A. 2
• B. 1
• C. 0
• D. more than 2

Answer 1

Answer: (C)

Since L.H.S. is an even integer and R.H.S. is an odd integer hence no solution.