Understanding and Calculating Matrix Determinants - Step by Step Guide

In summary, the conversation discusses how to find the determinant of a matrix with the given form, where "n" is the order of the matrix. One method mentioned is to add all other rows to the first row, resulting in a determinant of 0. The process is demonstrated with different values of n. The individual requesting help asks if there are any other methods to find the determinant.
  • #1
encomes
5
0
How can I get the determinant of this matrix?

1-n 1 ...1 1
1 1-n ...1 1
. . . .
. . . .
1 1 ... 1 1-n

I think that the answer is 0 but... why?

Thank you.
 
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  • #2
encomes said:
How can I get the determinant of this matrix?

1-n 1 ...1 1
1 1-n ...1 1
. . . .
. . . .
1 1 ... 1 1-n

I think that the answer is 0 but... why?

Thank you.
Is "n" here the order of the matrix? If so then, by a row reduction to diagonal or triangular form, you can show that the last row becomes all "0"s.
 
Last edited by a moderator:
  • #3
Thx for your reply, but I can't see how u get to this solution.. Can u show me the process?
Thanks again!
 
  • #4
Try this: add all of the other rows to the first row. What do you get?

(Try it with n= 2, 3, and 4 first.)
 
  • #5
Alright, so, if I have a determinant with n=4, i add all the rows to the first and i get (4-n +4-n +4-n +4-n), so, it's 0.

Is there any other process?

Thank you.
 

What is a determinant of a matrix?

The determinant of a matrix is a scalar value that is computed from the elements of the matrix. It is a measure of the matrix's size and how the matrix affects the linear transformation it represents.

How is the determinant of a matrix calculated?

The determinant of a matrix can be calculated using various methods, such as cofactor expansion, Gaussian elimination, or using properties of determinants. The method used depends on the size and structure of the matrix.

What is the significance of the determinant of a matrix?

The determinant of a matrix has several important applications in mathematics and science. It is used to solve systems of linear equations, determine invertibility of a matrix, compute volumes of parallelepipeds, and more.

What are the properties of the determinant of a matrix?

The determinant of a matrix has various properties, such as linearity, multiplicativity, and the fact that it changes sign when rows or columns are interchanged. These properties are useful in simplifying calculations and proving theorems involving determinants.

How does the determinant of a matrix relate to eigenvalues and eigenvectors?

The determinant of a matrix is closely related to the eigenvalues and eigenvectors of the matrix. In fact, the determinant of a matrix is equal to the product of its eigenvalues. This relationship is useful in finding eigenvalues and eigenvectors, as well as understanding the behavior of a matrix's transformation.

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