Game Development Reference
In-Depth Information
Figure 9.12
When you solve for the values of a quadratic equation, you determine if the parabola the equation
generates intersects with the x axis.
two solutions each because they intersect the
x
axis in two places. Parabola E has
no solutions because its origin lies above the
x
axis and it opens upward.
Standard Forms
If you consider the examples quadratic equations offered in the previous sec-
tions, you find that the standard form of the equation can prove useful as a way to
easily discern the basic features of the parabola the equation generates. To
recapitulate, consider again the extended form of the equation:
aðx hÞ
2
þ k
If you know the value of
a
, then you can determine how wide or narrow the
parabola is likely to appear. If
a
is positive, the parabola opens upward. If
a
is
