Game Development Reference
In-Depth Information
6. In the Chart panel, locate the Zoom field. Click the x axis control and set the
field value to
7. Click the y axis control and again set the field value
to
7.
7. Now click the Chart for Formula 1 button to generate the graph.
To experiment with the graph of the absolute value figure you see in Figure 10.31,
return to the upper equation composition area and change the value of the
y-intercept to 4, 5,
4, and
6. The changes you make to the y-intercept value
move the graph along the
y
axis without distorting it.
Flipping Across the Axis
Whether you are working with a linear or a non-linear equation, a negative
coefficient has the effect of reversing the slope of the graph. A typical scenario
with a linear equation involves seeing the line change so that instead of going
from quadrant III to quadrant I, the line goes from quadrant II to quadrant IV.
With a parabola, you see the vertex of the parabola flipped so that it opens downward.
Linear Flips
To use Visual Formula to show how changing the coefficient of a variable alters
the slope or orientation of a graph, you can start out by working with a linear
equation and generating a graph of a line with a positive slope. Then you can
create a line with a negative slope. The following sections review the necessary
steps. Refer to Figure 10.32 as you go.
The Positive Slope
Assume you are working with an equation that takes the form
y ¼ mðxÞþb
.To
implement this equation, work in the top equation composition area. Use the
following steps:
1. Click the menu item for Value. Then click in the equation composition area
to position the Value field. Type 2 in the Value field. This is the field that
corresponds to the coefficient
m
.
2. Click the Multiply menu item. Then click to the right of the Coefficient field
to position the multiplication sign.
3. Click the Value field again and position the field to the right of the multi-
plication sign in the equation composition area. Type x in this field.
