**v · u** = |**v**| |**u**| cos θ
= |**u**| |**v**| cos θ
= **u · v**

The dot product is **commutative**
The order of operands does not make any difference.

u · v=v · u.

Another property is:

0 · 0= 0

This means that the dot product of the *zero vector* with itself
results in the *scalar value* of zero.
There are two different kinds of zero in the equation.
The operands of the dot product are two vectors,
and the output is a scalar (a real number).

What is
a (**u · v**)
where "a" is a scalar?