## Precalculus: Mathematics for Calculus, 7th Edition

a) $[-3,5]$ b) $(-3,5]$
a) For interval notation, the closed points at $-3$ and $5$ mean that those points are included, and therefore each end is enclosed with a square bracket instead of a parenthesis. b) For interval notation, the open point at $-3$ means $x$ cannot be -3 so this is enclosed by a parenthesis, however the closed point at $5$ means that $x$ can be $5$ and therefore $5$ is enclosed with a bracket.