The dot product of two vectors a = [a 1, a2, …, an] and b = [b 1, b2, …, bn] is defined as: ab = a1b1+a2b2+…+anbn.
By matrix multiplication, take (column) vector as n× 1? Ma trix, dot product can also be written as: a b = a t * b, where at represents the transposition of matrix a.
concept
Linear algebra is a branch of algebra, which mainly deals with linear relations. Linear relationship means that the relationship between mathematical objects is expressed in linear form. For example, in analytic geometry, the equation of a straight line on the plane is a binary linear equation; The equation of spatial plane is a ternary linear equation, and the spatial straight line is regarded as the intersection of two planes, which is represented by an equation group composed of two ternary linear equations.
A linear equation with n unknowns is called a linear equation. A function whose variables are linear is called a linear function. Linear relation problem is called linear problem for short. The problem of solving linear equations is the simplest linear problem.