Answer
Interval notation : $\quad(-\infty,0]$
Inequality : $\quad x\leq 0$
Work Step by Step
Right bracket indicates that $0$ is part of the graph.
The shaded region is to the left of $0$ thus, the half open interval is $(-\infty,0]$.
It consists of all real numbers $x$ that are less than or equal to $0$.
Hence, the interval notation is $x\leq0 $.
