Game Development Reference
In-Depth Information
The multiplicative inverse of
2
is
3
. Your first slope was
2
3
, however, so when
you carry out the multiplication, you end up with
1.
2
3
3
2
¼
1
Exercise Set 7.4
Write the equations for the lines perpendicular to the given lines.
3
4
x þ 2
b. y ¼ 3x 2
a. y ¼
1
4
x þ 3
c. y ¼
2
3
x þ 2
e. y ¼3x
d. y ¼
Determine whether each set of equations represents perpendicular lines.
f. y ¼ 4x 5,
4y ¼ 8 x
g. 2x 5y ¼3,
2x þ 5y ¼ 4
h. y ¼ 5 3x,
y þ 3x ¼ 8
i. x 2y ¼ 5,
2x þ 4y ¼ 8
j. 2x þ 3y ¼ 1,
3x 2y ¼ 1
Depicting Absolute Values
You can view a given absolute value as representing two values, one positive and
one negative. Consider, for example, that you begin with an equation such as
y ¼jxj
. If you solve this equation for values ranging from 0 to 14, you end up
with the graph Figure 7.4 illustrates. The values of
x
extend in positive and
negative directions that reflect distances of the value from zero. The distances can
be negative or positive.
