Answer:
f(1) = 1
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.