X-intercept

Definition

The x-intercept is the point where a graph crosses the x-axis, where the y-coordinate is zero. It represents the solution(s) to an equation when $y = 0$.

5 Must Know Facts For Your Next Test

1. The x-intercept can be found by setting $y = 0$ in the equation of the line or curve.
2. For linear equations in slope-intercept form $y = mx + b$, the x-intercept is found by solving $0 = mx + b$.
3. A graph can have more than one x-intercept, especially if it is a polynomial of degree greater than one.
4. In standard form $Ax + By = C$, solve for $x$ when $y = 0$ to find the x-intercept: $Ax = C \Rightarrow x = \frac{C}{A}$.
5. The coordinates of an x-intercept are generally written as $(a, 0)$ where 'a' is the value on the x-axis.

Review Questions

• How do you find the x-intercept of a linear equation given in slope-intercept form?
• What are the coordinates of an x-intercept?
• Can there be multiple x-intercepts in a single graph? If so, provide an example.

Related terms

Y-Intercept: The y-coordinate where a graph crosses the y-axis, occurring when $x=0$.

Slope:

A measure of how steep a line is, calculated as the ratio of rise over run between two points on a line.

Linear Equation:

An equation that forms a straight line when graphed; generally expressed in forms like slope-intercept ($y=mx+b$) or standard form ($Ax+By=C$).