Question

Number of solutions of the equation $sin(\frac{1}{3}co{s}^{-1}x)=1$ are

• A. only one
• B. no solution
• C. only three
• D. at least two

Answer 1

Answer: (B)

$sin(\frac{1}{3}co{s}^{-1}x)=1$
$\Rightarrow co{s}^{-1}=\frac{3\pi }{2}$
$\Rightarrow \exists$ no solution, as $x\in [0,\pi ]$