My Math Forum Determinant proof for 3 by 3 matrices

 Linear Algebra Linear Algebra Math Forum

 June 3rd, 2014, 11:24 AM #1 Member   Joined: Nov 2013 Posts: 47 Thanks: 4 Determinant proof for 3 by 3 matrices To get the determinant of 3 by 3 matrices we're told to just reduce the 3 by 3 matrix into three 2 by 2s by essentially taking 3 terms in the matrix and eliminating their column and row and then multiplying those terms by their respective 2 by 2 sub-matrices. I'm able to use the method, but I don't like blindly applying methods like this without having at least some intuition of why they work. I've looked at a geometric proof for why the determinant of a 2 by 2 matrix is ad-bc and it makes sense, but I havent been able to find a proof for the method that I described above. Why in the world does that work?
 June 4th, 2014, 08:18 PM #2 Newbie   Joined: Jun 2014 From: USA Posts: 21 Thanks: 2 It is possible by multiplication only there is not any other option to change 3 by 3 matrix in 2 by 2.

 Tags determinant, matrices, proof

### proof for"3by3"matrix

Click on a term to search for related topics.
 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post ungeheuer Linear Algebra 1 August 31st, 2013 02:15 PM OliverRunner Linear Algebra 2 January 25th, 2013 11:22 AM leaf.coffee Linear Algebra 1 December 15th, 2012 07:54 AM thedinuka Linear Algebra 3 August 10th, 2012 05:37 AM serenaxiuli Algebra 0 April 11th, 2009 07:11 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top