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A simple Linear Algebra question that seems so hard

  • Thread starter qwerty11
  • Start date
  • #1
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Homework Statement



Is the statement true or sometimes false. Justify your answer:

The determinant of a matrix is unchanged if the columns are written in reverse order.

Homework Equations





The Attempt at a Solution



I understand that the only thing that is changed is the sign (negative to positive or visa-versa), but do not understand the proof of how.
 

Answers and Replies

  • #2
1,033
1
how do you find the determinant of a matrix?
 
  • #3
39
0
One way would be via cofactor expansion.

I.e. 3x3 matrix determinant =a11C11+a12C12+a13C13
 
  • #4
1,033
1
okay good. so if you switched the columns, how would the cofactor expansion change?
 
  • #5
1,033
1
and calculate out those cofactors when you do it.
 

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