## Precalculus (6th Edition)

$y$
RECALL: The graph of the function $y=f-x)$ involves a reflection across the y-axis of the parent function $y=f(x)$. The parent function of the given function is $y=|x|$. Since the function is of the form $y=f(-x)$, then it involves a reflection across the y-axis of the parent function $f(x)=|x|$. However, since the $f(x)=|x|$ is symmetric with respect to the y-axis, the graph of $f(x)=|-x|$ is the same as the graph of $y=|x|$. Therefore, the missing expressions in the given statement is: $y$