Use the graph of f(x) to find the indicated function values.

if x = 0, then f(0) = .

if f(x) = 0, then x = .

Using the graph, it is found that:

If x = 0, then f(0) = 1.If f(x) = 0, then x = -1.

------------------------------

We get that x = 0, and want to find f(0).This is the value of the y-axis(vertical axis) when the x-axis(horizontal axis) is 0.From the graph, we get that when , and thus, f(0) = 1.

------------------------------

The value of x when f(x) = 0 is the value of the x-axis when the y-axis is 0.From the graph, we get that when , and thus: If f(x) = 0, then x = -1.

A similar problem is given at link

Horizontal change or the change of x