Write the function whose graph is the graph of $y=|x|$, but is shifted down 9 units. \[ y= \]

Step 1 ：The function \(y=|x|\) is the absolute value function.

Step 2 ：When we say that the graph is shifted down 9 units, it means that we subtract 9 from the function.

Step 3 ：So, the new function becomes \(y=|x|-9\).

Step 4 ：\(\boxed{y=|x|-9}\) is the function whose graph is the graph of \(y=|x|\), but is shifted down 9 units.