Question

Below are two different functions, f(x) and g(x). What can be determined about their y-intercepts? x g(x) 2 4 4 6 6 8

Answer 1

They both have the same y-intercept.

Answer 2

Remember the y-intercept is the y-coordinate of the function for x = 0.

From the graph, the function f(x) is constant, f(x) = 2, so the y-intercept of f(x) is 2.

From the table:

x g(x)

2 4
4 6
6 8

You do not know the value of the function g(x) for x = 0. Only if you were told that g(x) is a line or you had some other information you might infere the y-intercept of g(x).

For example if g(x) is a straight line you can conclude that g(0) = 2, and that meant that the y-intercepts of f(x) and g(x) are equal.