請問一下這一題敘述用這種方式解釋對嗎？
(2)The rank of a m*n matrix A can not be zero, the term "full rank" means the rank of A equals m.
[自解]
No!零矩陣無rank,且full rank=min(m,n)，即m,n中取最小值，不一定等於m
那想請問以下兩題是對的還是錯的？又該怎麼解釋呢？我不會寫
(7)Let Rref is the reduced row echelon form of matrix A, then the column space exactly equal to C(Rref) and the same for null space N(A)=N(Rref)
(9)IF rank of A, an m*n matrix, is n, then the nullity(i.e. dimension of null space) is 0.
