1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Factoring a constant from each row of matrix

  1. Apr 13, 2009 #1
    Why is it that a 16 comes out when you factor a 2 from each row of this matrix:

    0 2 2 2
    2 0 2 2
    2 2 0 2
    2 2 2 0
     
  2. jcsd
  3. Apr 13, 2009 #2

    dx

    User Avatar
    Homework Helper
    Gold Member

    Because 2*2*2*2 is 16 (one for each row). Determinants are linear in both columns and rows, so if you divide a column by 2, the determinant also becomes half as much as it was before. If you want to keep the value of the determinant the same, you have to multiply it by 2. So when you divide the first row by 2 to make it (0, 1, 1, 1), you have to multiply the whole thing by 2.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Factoring a constant from each row of matrix
Loading...