Tamara J. answered • 12/04/12

Math Tutoring - Algebra and Calculus (all levels)

The **y-intercept** is the point at which the line crosses the y-axis -- that is, it is the point where x=0, yielding the coordinate (0, y).

Conversely, the **x-intercept** is the point at which the line crosses the x-axis -- that is, it is the point where y=0, yielding the coordinate (x, 0).

The **slope** is the average rate of change from one point to the next on a given line. In other words, it is the ratio of the vertical change (change in y) to the horizontal change (change in x) between any 2 points on a line.

That is,

slope = vertical change / horizontal change

= change in y / change in x

= Δ y / Δ x

So for any 2 points on a line, (x_{1}, y_{1}) & (x_{2}, y_{2}), the slope is: y_{2} - y_{1} / x_{2} - x_{1}