Appendix A - Review - A.9 Interval Notation; Solving Inequalities - A.9 Assess Your Understanding - Page A79: 16

Interval notation : $\quad(-1,2)$ Inequality : $\quad-1\lt x \lt 2$

Left and right parentheses indicate that $-1$ and $2$ are not part of the graph. Thusm the open interval is $(-1,2)$. It consists of all real numbers $x$ that are greter than $-1$ but less than $2$. Hence, the interval notation is $-1\lt x \lt 2$.