In Exercises 1-2, (a) does the equation Ax = 0 have a nontrivial solution and (b) does

Question:

In Exercises 1-2, (a) does the equation Ax = 0 have a nontrivial solution and (b) does the equation Ax = b have at least one solution for every possible b?
1. A is a 3 ( 3 matrix with three pivot positions.
2. A is a 4 ( 4 matrix with three pivot positions.