Question

Which of the following functions has a well-defined inverse?

1) f(a) = 1
2) f(b) = 2
3) f(c) = 3
4) f(d) = 4

Answer 1

Only the function f(d) = 4 has a well-defined inverse because it is one-to-one.

Step-by-step explanation:

A function has a well-defined inverse if and only if it is one-to-one. A function is one-to-one if for every element in the domain, there is a unique element in the range. In this case, only the function f(d) = 4 has a well-defined inverse.

This is because it is the only function that is one-to-one, as there is a unique element (d) in the domain that maps to a unique element (4) in the range.