Precalculus (6th Edition) Blitzer

The solution on the interval $[0,2\pi )$, correct to four decimal places, is $0.9695$ or $2.1720$.
We have to calculate the equation using a calculator; we keep the calculator in radian mode to find the inverse sine of $0.8246$. $\theta =\text{si}{{\text{n}}^{-1}}0.8246\approx 0.9695.$ Therefore, the sine is positive in quadrants I and II, thus, $x\approx 0.9695\$ or $x\approx \pi -0.9695.$ And the value of $\pi$ is 3.14159. Hence, the value of $x$ is: \begin{align} & x\approx 3.14159-0.8246 \\ & \approx 2.1720. \end{align}