  Math Central - mathcentral.uregina.ca  Quandaries & Queries    Q & Q    Topic: 3 by 3   start over

2 items are filed under this topic.    Page1/1            The evaluation of a 3 by 3 determinant 2016-02-19 From Kristen:What is the step-by-step process on how to evaluate the determinant of a 3*3 matrix, using the expansion method (not the diagonal method)Answered by Penny Nom.     Determinants 2008-05-02 From Henry:I have a question about solving 3x3 matrices. The traditional way, or at least the way I've been taught, is that if one has a 3x3 matrix such as: [ a b c ] [ d e f ] [ g h i ] one solves it according to this formula: [ei - hf) - (bi - hc) + (bf - ec) = determinant. According to a book I'm now studying to prepare for the California CSET exam, there is another, easier, way to solve it: [ a b c ] [ a b ] [ d e f ] [ d e ] [ g h i ] [ g h ] In other words, one repeats the first two rows of the matrix and adds them to the right. At this point, the determinant is calculated thus: (aei) +(bfg) + (cdh) - (gec) - (hfa) - (idb). Is this, in fact, correct?Answered by Harley Weston.      Page1/1    Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.    about math central :: site map :: links :: notre site français