Find the function that is finally graphed after the following transformations are applied to the graph of $y=\sqrt{x}$ in the order listed.
(1) Shift down 9 units
(2) Reflect about the $x$-axis
(3) Reflect about the y-axis
\[
y=
\]

Step 1 ：The transformations applied to the function \(y=\sqrt{x}\) are shifting down by 9 units, reflecting about the x-axis, and reflecting about the y-axis.

Step 2 ：To shift a function down by 9 units, we subtract 9 from the function. So, the new function becomes \(y=\sqrt{x}-9\).

Step 3 ：Reflecting a function about the x-axis means changing the sign of the function. So, the new function becomes \(y=-(\sqrt{x}-9)\).

Step 4 ：Reflecting a function about the y-axis means changing the sign of the variable inside the function. So, the new function becomes \(y=-\sqrt{-x}-9\).

Step 5 ：However, it should be noted that the function \(y=-\sqrt{-x}-9\) is not defined for positive values of \(x\). This is because the square root of a negative number is not a real number. Therefore, the graph of the function only exists for \(x\leq0\).

Step 6 ：\(\boxed{y=-\sqrt{-x}-9}\) is the function that is finally graphed after the transformations are applied to the graph of \(y=\sqrt{x}\).