Proved by: Not Applicable
References: Kernel, Image of Linear Transformation
Justifications: Not Applicable

Specializations: Not Applicable
Generalizations: Not Applicable

Solutions to

Let be a linear transformation. The system of linear equations has

  1. at most one solution for every iff .
  2. at least one solution for every iff .

Proof.

  1. If the kernel of is not , then there is more than one solution to . (Of course, one solution is ).
    In the other direction, if there exists a for which has more than one solution, i.e.,


    So is a nonzero element of the kernel, so .
  2. Saying that is exactly saying that is onto.