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anonymous
 5 years ago
Somebody help me calculate the determinant of a 4*4 matrix..
anonymous
 5 years ago
Somebody help me calculate the determinant of a 4*4 matrix..

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0If the matrix is diagonal then the determinant is the product of its diagonal entries. If it is not diagonal you can simplify the matrix using elementary row operations (which can change the sign of the determinant) to a diagonal matrix. Alternatively you can directly compute it without any simplification, but it can be more tedious. There is a 4x4 example here: http://people.richland.edu/james/lecture/m116/matrices/determinant.html under "larger order determinants"

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0To directly compute,multiply each entry in the first row against the determinant of the 3x3 matrix formed by eliminating the top row and the column containing your current entry.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0^ then alternatively add and subtract the determinants for the 3x3 matrices

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0is there any other method that can be used since the above one..is a bit tedious and long when your doing a two hours paper.......

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Do you need to show your work ?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yes its required you show your work...

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0What is the matrix? It can't be that bad :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[\left[\begin{matrix}1 & 2 &3&4 \\ 2 & 1&2&1\\3&7&1&2\\1&3&2&1\end{matrix}\right]\]..you do that for me i'll certainly do the rest..:)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0See attached. Hope that helps.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0cse thankyou was however wondering if you don't breakdown the 3*3 to show how you come up with the determinant again,,,

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Sure np. I was just being lazy when I typed that up and skipped the 3x3 part. See attached.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0The main idea is you keep breaking up the big matrix into smaller matrices that you can calculate the determinant for. It will possibly be more confusing if I write a really lengthy post on how to do this but look at the diagram I drew and check out the video below: http://www.youtube.com/watch?v=21LWuY8i6Hw
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