Let x x1 x2 x3 x4 be a vector in R4 There are 24 ways to re
     Let x = (x_1, x_2, x_3, x_4) be a vector in R^4. There are 24 ways to rearrange these 4 entries into another vector, like (x_2, x_1, x_3, x_4) and (x_4, x_3, x_2, x_1). Those 24 vectors, including z itself, span a subspace S. Pick specific vectors x so that the dimension of that subspace is (a) zero, (b) one, (c) three, (d) four.  
  
  Solution
a . when x= (0,0,0,0) then the subspace will have only \'x \' asits element and its dimension is 0
b . when x= ( a,0,0,0)
then the subspace S consists of all elements of the form = { (a,0,0,0) / a isin R }
Basis of S is B1 = { ( 1,0,0,0) } and the dimension is 1 .
c =. when x = ( 1,2,3,0)
Basis of the subspace B2 = { (1,0,0,0) , (0,2,0,0) , (0,0,3 ,0) , (0,0,0,0) }
hence the dimension =3
d when X= (1,2,3,4)
basis of the subapce = B3= { ( 1,0,0,0) , (0,2,0,0) ,(0,0,3,0) , (0,0,0,4) }
dimension of the subspace =4

