Expanding by Minors: Understanding the Process of Computing Determinants

  • Thread starter Thread starter brad sue
  • Start date Start date
  • Tags Tags
    Determinant
brad sue
Messages
270
Reaction score
0
Hi guys, what doe it mean when we are asked to compute the determinant the following way:

compute determinant across first row, down second column:
|1_0_3|
|2_2_1|
|4_0_3|

I know how to compute but here I need to understand the way to do it.

Thank you
B
 
Physics news on Phys.org
They are likely asking you to compute the determinant in two ways:
(1) Across the first row
(2) Down the second column
As you know, you can expand the determinant across any row or column.
 
It's talking about "expanding by minors". Do you know how to do that?
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top