We call the elements of a vector space vectors and the elements of the field scalars.For instance,R",the set of real column vectors 1 also written as (1,x2,....n)T (r for transpose)is a vector space over R with respect to the addition (c1,2,,xn)T+(1,2,,n)T-(c1+1,2十2，，n十n)T and the scalar multiplication c (1,22,....In)T (cx1;cx2;...,cun)T,cR. 44