let vector a=-4i+3j-alphak, vecto b=2i+alphaj+k and vector c=5i-j+alphak, where alpha is a real number. Show that the vector c is not in the space spanned by vectors a and b. Can anyone help me to work out this sum pls.

Question

jamesj · Answer

Several ways to do this.  One way is this.  Suppose c is in the span of a and b.  Then there exist constant p and q such that
c = pa + qb

Show that now leads to a contradiction.

anonymous · Answer

Thanx a lot for the help James.