A vector =(a 1, a2) b vector =(b 1, b2) a vector +b vector =(a 1+b 1, a2+b2) Subtraction is the same.

The vector a is parallel to the vector b: a 1b 1=a2b2.

Vertical: a 1b 1+a2b2=0.

* * * Line: A vector =m times B vector (m is constant), that is, a 1=m times b 1, a2=m times b2.

A vector times b vector =a 1b 1+a2b2.

The modulus of vector a = (the square of a1+the square of a2) opens the square root.

Generally speaking, it is relatively simple to quantize a vector into a coordinate vector.