- Answer 1: it is
Vector(x2-x1,y2-y1) - Answer 2: Normalizing means to scale the vector so that its length is 1. It is a useful operation in many computations, for example, normal vectors should be specified normalized for lighting calculations in computer graphics. The normalized vector of
v(x,y)isvn(x/Length(v), y/length(v)).
HTH