Linearly Independent Columns of a Matrix

Click For Summary

Discussion Overview

The discussion revolves around the concept of linear independence of columns in a matrix, specifically in relation to the determinant of the matrix. Participants explore the implications of a non-zero determinant on the linear independence of the column vectors, touching on theoretical aspects and practical understanding relevant to linear algebra.

Discussion Character

  • Technical explanation, Conceptual clarification, Homework-related

Main Points Raised

  • One participant inquires whether a matrix P with a non-zero determinant implies that its columns are linearly independent.
  • Another participant asserts that a non-zero determinant indicates that P is invertible and thus has maximal rank, suggesting linear independence of the columns.
  • A later reply elaborates on the reasoning behind the non-zero determinant, explaining that it relates to the ability to transform the matrix into upper diagonal form and the significance of having non-zero entries on the diagonal.
  • One participant expresses gratitude for the clarification, indicating that they found the explanation helpful in the context of preparing for an exam.

Areas of Agreement / Disagreement

Participants generally agree that a non-zero determinant is associated with linear independence of the columns of a matrix, although the discussion includes varying levels of detail and understanding regarding the underlying concepts.

Contextual Notes

Some assumptions about the properties of determinants and matrix operations are present, but not all participants may share the same level of familiarity with these concepts. The discussion does not resolve all nuances related to singular and non-singular matrices.

Who May Find This Useful

Students studying linear algebra, particularly those preparing for exams or seeking clarification on matrix properties and linear independence.

sajama
Messages
5
Reaction score
0
Hi wondering if can anyone help me... I've gotten so bogged down in all the rules and stuff for singular/non-singular matrices I've completely confused myself!

Can anyone tell me is it true to say that if I have a matrix P, det(P) is NOT EQUAL to 0, then the vectors that would form the columns of P are linearly independent?

Cheers
 
Physics news on Phys.org
Yes because then P is invertible, and thus have maximal rank.
 
Brilliant - cheers! :)
 
do you know why this is true? i.e. do you know what it really means that the determinant is not zero?

recall that any matrix can be rendered into upper diagonal form by repeatedly performing row operations, hence also by repeatedly multiplying by special invertible matrices.

then the determinant is non zero iff the final matrix is actually diagonal and has non zero entries on the diagonal. these can then be made 1's.

hence it has been inverted by matrix multiplication, and the columns are visibly independent, hence were also originally.
this is just one of many ways to see it.
 
Thank you - it does make sense now - I had a Linear Maths exam this afternoon and even though at some stage I had understood the reasoning behind what made a matrix singular, my mind seemed to be blanking on me in the hours leading up to the exam!

Thanks again for the help :)
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 14 ·
Replies
14
Views
4K
  • · Replies 14 ·
Replies
14
Views
4K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K