Answer
The domain of this function is all real numbers except $9$.
Work Step by Step
To find the domain of this function, we need to find which values are excluded for $x$. In a rational function, the denominator cannot equal $0$ because the function would be undefined. Therefore, we need to set the denominator equal to $0$ and solve for $x$:
$x - 9 = 0$
Add $9$ to each side to solve for $x$:
$x = 9$
This represents the value that $x$ cannot be. Therefore, the domain of this function is all real numbers except $9$.
