Example4.9.5Using Slope Triangles

Although making a table is straightforward, the slope triangle method is both faster and reinforces the true meaning of slope. In the slope triangle method, we first identify some point on the line. With a line in slope-intercept formĀ (4.5.1), we know the \(y\)-intercept, which is \((0,1)\text{.}\) Then, we can draw slope triangles in both directions to find more points.

This is a graph of the line y=-2x+1. The following points on the line are plotted: (-2,5),(-1,3),( 0,1),(1,-1),(2,-3). There are a few slope triangles. One starts at (-2,5), passes (-1,5), and ends at (-1,3). One    starts at (-1,3), passes (0,3), and ends at (0,1). One starts at (0,1), passes (1,1), and ends at (1,-1). One starts   at (1,-1), passes (2,-1), and ends at (2,-3).
Figure4.9.6Marking a point and some slope triangles
Figure4.9.7Graphing \(y=-2x+1\) by slope triangles

Compared to the table method, the slope triangle method:

in-context