Question

How do you determine whether the function `p(x)=-4` has an inverse and if it does, how do you find the inverse function?

Answer 1

For a function `p(x)` to have an inverse it needs to be one-to-one, each different value of `x` yielding a different value of `p(x).` Since here all different values of `x` yield the same value for `p(x)`, `p` is not invertible.