Note that for any vector ar, we have
a +0
r
r
 = 0
a
a
+
=
r
r
r
Here, the zero vector 0
r  is called the additive identity for the vector addition 10 5  Multiplication of a Vector by a Scalar
Let ar  be a given vector and λ a scalar Then the product of the vector ar  by the scalar
λ, denoted as λ ar , is called the multiplication of vector ar  by the scalar λ