FINDING THE SLOPES OF LINES

Recall that the slope of a line passing through points (x1, y1) and (x2, y2) is:
m =  rise
run
=
 y2 - y1 x2 - x1

For the exercises below, moving your mouse across the graph allows you to control which line is shown. If you slide your mouse off the bottom edge of the graph, the chosen line will remain visible. When you have selected a line, you may test if it has one of the slopes named in 7 problems below.

 Move the mouse arrow slowly across the graph at the right. THE RED LINE WILL MOVE. To keep a chosen line visible, slide your mouse off the bottom edge of the graph.

 [1] Use your mouse to show a red line with slope = -2 ; when you are done,
 [2] Use your mouse to show a red line with slope = +2 ; when you are done,
 [3] Use your mouse to show a red line with slope = + ½ ; when you are done,
 [4] Use your mouse to show a red line with slope = - ½ ; when you are done,
 [5] Use your mouse to show a red line with slope = +1 ; when you are done,
 [6] Use your mouse to show a red line with slope = - 1 ; when you are done,
 [7] Use your mouse to show a red line with slope = 0 ; when you are done,
 [8] Use your mouse to show a red line with undefined slope ; when you are done,