Graphics Reference
In-Depth Information
then
−
1
−
v
=
−
2
Figure 2.5 shows the graphic interpretation of this sign reversal.
Y
Y
3
3
2
2
v
-v
1
1
2
1
X
1
2
X
Figure 2.5.
A vector can be multiplied by any positive or negative scalar to make it larger or smaller. For
example, we could double a vector by multiplying it by 2: given
1
2
v
=
then
2
4
2
v
=
and
2
1
1
2
v
=
Equally, vector addition and subtraction obey the same rules as scalars. For example, given two
vectors
1
2
and
w
2
1
v
=
=
then
1
3
3
+
2
v
+
w
=
=
2
+
1
In contrast,
1
−
−
2
1
1
v
−
w
=
=
2
−
1
