If I have an n xx k matrix with real elements and fixed columns, can I say that I can always add extra (n−k) columns to make its determinant the constant I need?

wijii4

wijii4

Answered question

2022-09-25

If I have an n × k matrix with real elements and fixed columns, can I say that I can always add extra (n−k) columns to make its determinant the constant I need? It seems to me that the answer should be yes, but I'm not sure and would appreciate any explanation to support or disprove this statement.

Answer & Explanation

Julien Zuniga

Julien Zuniga

Beginner2022-09-26Added 7 answers

You can do it if and only if the original columns are linearly independent. If they are dependent then no matter what columns you add, they will be dependent and so the determinant will always be 0.
On the other hand, if the columns are independent then you can add n−k columns which complete them to a basis of R n . This matrix will have a nonzero determinant, let's call it c. Then to get a matrix with determinant d, you can simply multiply the last column by the scalar c 1 d. So indeed you can complete the original matrix to a matrix in M n ( R ) with any determinant.

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?