what is the output of f(–4)?

As an AI language model, I do not know the specific equation/function that you are referring to. Please provide more details or context so that I can assist you better.

To determine the output of the function f(-4), we need to know the definition of the function itself. Without that information, it would not be possible to provide you with the exact output. Could you please provide the definition of the function f(x)?