Question

If f(x) is a function and f(1) = 5, then which of the following could not be true?
a.)f(1) = 1
b.)f(2) = 1
c.)f(5) = 5

Answer 1

The choice a could not be true because the value of f(1) is already equal to 5. Therefore, the value of f(1) cannot be 1. This is one of the properties of a function that for every value of x, there should be only one corresponding value of y.