Calculation of point multiplication formula a b = | a || b | cos θ. Dot multiplication is also called dot product. Mathematically, dot product, also known as scalar product, refers to a binary operation that accepts two vectors on real number R and returns a real scalar. It is the standard inner product of Euclidean space.

There are two ways to define point product: algebraic method and geometric method. Cartesian coordinate system is introduced into Euclidean space. The dot product between vectors can be obtained by algebraic operation of vector coordinates, and can also be solved by introducing geometric concepts such as length and angle of two vectors.