Problem

The key is to unpack the absolute value into two cases, then solve each linear inequality for $\sin x$. Since $\sin x$ is monotonically increasing on the given interval, once you find the range of valid sine values, you can use inverse sine to convert back to $x$-values. Pay attention to which endpoints are included—the strict inequality matters.

The key is to unpack the absolute value into two cases, then solve each linear inequality for $\sin x$. Since $\sin x$ is monotonically increasing on the given interval, once you find the range of valid sine values, you can use inverse sine to convert back to $x$-values. Pay attention to which endpoints are included—the strict inequality matters.