Creation of this applet was inspired by the work of Steve Phelps:
https://tube.geogebra.org/material/simple/id/45576
Directions:
1) Examine the equation shown in purple below.
2) Drag points A & B so that the line that passes through these points is the graph of the equation displayed.
3) If you're correct, the applet will inform you. If you don't notice anything, keep trying until you position the green line correctly.
4) After correctly graphing the line, click the "Generate New Line" button. This will cause a new equation to appear.
5) Repeat steps (1) - (4) as many times as you need until you've mastered this concept.
6) As an additional challenge, try to complete steps (1) - (4) WITHOUT putting either point on the y-axis!