Y-Intercept Definition: a plain-English explanation of what the term means, why it matters in math, and how it is used, followed by worked examples and practice questions so the definition turns into something you can apply.
Math Dictionary / Y-Intercept
Y-Intercept
The y-intercept is the point where a graph crosses the y-axis.
AlgebraGrade 8Algebra 1GEDSATACT
What it means
In y = mx + b, the y-intercept is b.
Also called: vertical intercept
Examples
| In y = 2x + 5, the y-intercept is 5 |
| A graph crosses the y-axis at x = 0 |
| The point can be written as (0, b) |
Common mistake
The y-intercept is not always where the graph crosses the x-axis.
Try one
Question: What is the y-intercept of y = -3x + 8?
Show answer
The y-intercept is 8.