Dot product (also known as scalar or inner product).
For two vectors, mathematically represented as
a =
a1,a2,...,an and
b = b1,b2,...,bn, the dot product is
a . b = a1*b1 + a2*b2 + ... + an*bn.
Some properties are derived from this. The dot product of a vector
with itself is the square of its magnitude (
norm), and the dot
product of two orthogonal vectors is zero.