A slope grapher is a computer program that plots several points of a given equation, and then connects all of the points with a single line, thus illustrating the slope of the equation. Such programs are widely used by the TI-83 and TI-84 calculators.
Slope is defined as the difference between two "y" variables divided by the difference in two "x" variables. Dividing these values yields the slope between the two points.
It is possible to graph an equation without the program so long as the slope and the y-intercept are given. The y-intercept is where the line crosses the y-axis.