Game Development Reference
In-Depth Information
Perpendicular Lines
Figure 7.2 provides an illustration of a basic linear function
y ¼
3
x þ
2. The
y-intercept is 2. The slope is 3. The line extends upward into quadrant I
since the slope is positive. You see three coordinates on the line, the top of which
is (2, 8). At the same time, the graph features a second line, one that slopes
downward into quadrant IV. This second line runs perpendicular to the first line.
It intersects the
x
axis at (6, 0).
To create an equation that generates a line that is perpendicular to another line,
consider in Figure 7.2 the equation that generates the line with the positive slope.
The y-intercept is at (0, 2). The line slopes up into quadrant I. In addition to this
Figure 7.2
The inverse creates a perpendicular line.
