Question

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

Answer 1

Answer:

f(1) = 1

Step-by-step explanation:

A function can have only one value of y for a given value of x.

Thus, if f(1) = 5, we cannot have f(1) = 1.

We can have f(2) =1 and f(5) = 5, because these are values of y for different values of x,

The first diagram below is the graph of a function, because there is only value of y that corresponds to a given value of x.

The second diagram is not the graph of a function, because there are two values of y that correspond to a given value of x.

However, the top semicircle and the bottom semicircle separately are graphs of functions, because they each have only value of y that corresponds to a given value of x.