Are the following statements true or false? Here A is an n by n square matrix.
1. If A is not invertible then the system A(vector x) = vector b has infinitely many solutions.
2.The zero matrix is invertible.
3.The product of two elementary matrices is an elementary matrix.
4. If A is invertible then so is A^T.
1. Not true
A is not invertible,
Also it has no solution.
2. Not true.