Answer
$0.73, 2.41$.
Work Step by Step
The domain of $\sin^{-1}{x}$ is the range of $\sin{x}$, which is $[−1, 1] $.
The range of $\sin^{-1}{x}$ is a specified domain of $\sin{x}$, i.e. $\left[− \frac{\pi}{2} , \frac{\pi}{2} \right]$.
This equation is the same as: $\sin(\theta)=\frac{2}{3}$ because $3\sin(\theta)-2=0\\3\sin(\theta)=2\\\sin(\theta)=\frac{2}{3}$
After using a calculator in radian mode the solutions for $\sin^{-1}{\frac{2}{3}}$ is $0.73$ (given by the calculator) and because the sine function is symmetric to $x=\frac{\pi}{2}$ the second solution is: $\frac{\pi}{2}+(\frac{\pi}{2}-0.73)\approx2.41$.
