2 1. Suppose thatAis a matrix with R(A) = span1210,1021R(AT ) = span1111, 1 1 -1 -1 [2] (a) How many rows and how many columns doesAhave?
[2] (b) What are rank(A), dim(N(A)) and dim(N(AT))?
[2] (c) For what numbersaandbare the vectors [2, a,-1,0]Tand [1,0,-1, b]T contained in N(AT )?