A , B are nXn matrices
prove that the space spanned by A's row equals the space spanned by A's columns
i know that there dimentions are equals
so in order to prove equality i need to prove that one is a part of the other
how to do it?
each column i of (AB)_i=A*B_i
i was told by my proff that that column i of AB is a member from the span of the columns of A
but i dont get this result
suppose the member of B_i column is (c1,c2,..,cn)
so the multiplication of A by the B_i column
we get then the first member is dot product from the first row with (c1,c2,..,cn)
i cant see how its a variation from the A columns?