If a function $f$ is evaluated at -9 , the value of the function is 0 . Write this situation using function notation. What is the function notation?

Step 1 ：The function notation is a way to represent a function that is a relation between inputs and a set of permissible outputs with the property that each input is related to exactly one output. In this case, the function notation for the given situation would be f(-9) = 0. This means that when the function f is evaluated at -9, the output is 0.

Step 2 ：Final Answer: \(\boxed{f(-9) = 0}\)