The dot product of vectors is also know as the “scalar” product.
#### Formula
If <spanclass="texhtml"><strong>a</strong></span> and <spanclass="texhtml"><strong>b</strong></span> are two vectors meeting at a point, whose moduli are |<spanclass="texhtml"><strong>a</strong></span>| and |<spanclass="texhtml"><strong>b</strong></span>| respectively and <spanclass="texhtml"><strong>θ</strong></span> is the angle between them, then the “dot” or “scalar” product of the two vectors is given as:
Also, if the two vectors (<spanclass="texhtml"><strong>a</strong></span> and <spanclass="texhtml"><strong>b</strong></span>) are given in terms of their [unit vectors](https://en.wikipedia.org/wiki/Unit_vector), where
Since <spanclass="texhtml"><em>i</em></span> and <spanclass="texhtml"><em>j</em></span> are [unit vectors](https://en.wikipedia.org/wiki/Unit_vector) (equivalent to one), then