The game: get the green function f(x) to pass through the blue points [math](x_1, y_1[/math]) and [math](x_2, y_2)[/math]. [br][br]To reset, click the top-right corner. [br][br]The function [i]f[/i] is controlled by [i]m[/i] and [i]b[/i], or [i]rise[/i], [i]run[/i], and [i]b[/i] at left. To get more precise values, type them into the input bar at the bottom. For example, you might have to type "m=8/3". [br][br]The points can be moved by clicking and dragging. They will snap to integer values if close enough. Or, in the input bar, you can type in [i]A=(x, y)[/i] for whatever values you like.[br][br]There are various checkboxes that show or hide information. Have fun! Send me feedback!

Keep [math](x_1, y_1)[/math] somewhere on the y-axis to start, and experiment by moving the other point around.[br]Can you predict when [i]m[/i] must be negative? [br]What if the points are horizontal? Vertical?