Answer
$0.42, \space 2.73$
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. $\left[− \frac{\pi}{2} , \frac{\pi}{2} \right]$.
After using a calculator in radian mode the solutions for $\sin^{-1}{(0.4)}$ is $0.41$.
The second solution can be found by subtracting $0.41$ from $\pi$ to obtain:
$\pi-0.41\approx2.73$