freeCodeCamp/guide/english/mathematics/x-and-y-intercepts/index.md

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title: X and Y Intercepts
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## X and Y Intercepts

The X intercept(s) are the point(s) on the X axis where the graph of the function crosses or touches the axis. They occur where ```y = 0```. 

The Y intercept is the point at which the graph of the function crosses the Y axis. It occurs where ```x = 0```. 

A function can have multiple X intercepts, but can only have a single Y intercept. Why is only a single Y intercept allowed? By definition, a function can only have one output, y, for each unique input, x. Thus, a graph would violate this definition if ```x = 0``` produced more than one output, y.

To find the X intercept(s), set ```y = 0``` and solve the equation for x. 

To find the Y intercept, set ```x = 0``` and solve the equation for y. 

As an example, the X and Y intercepts have been solved for a typical line in the form ```y = mx + b```.
![An image demonstrating finding the x and y intercepts for a typical line in the form of y = mx + b . The Y intercept is equal to b and the X intercept is equal to negative b divided by m](https://raw.githubusercontent.com/hayleycd/images/master/solve_intercepts.jpeg)