Let AAA be a 3×33 \times 33×3 matrix such that Ax=bAx = bAx=b has infinitely many solutions. Which is true?
det(A)≠0\det(A) \neq 0det(A)=0
rank(A)<3\text{rank}(A) < 3rank(A)<3
The columns of AAA are linearly independent
AAA is the zero matrix