Calculation method of space vector

Calculation method of space vector

The distance formula between two points, if a (x1, x2) B (Y1, Y2), then the absolute value of the module of AB = the length formula of the root sign [(x1-y1) ^ 2 + (x2-y2) ^ 2] vector, if the module of a = (A1, A2), then the absolute value of the module of a = the coordinate formula of the angle between two vectors, if a (A1, A2) B (B1, B2), then cos = (a * b) /