1. Not finding help here? Sign up for a free 30min 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!

System of linear equations

  1. Oct 27, 2014 #1
    1. The problem statement, all variables and given/known data
    I'm given a system of equations and I'm told to:
    Solve this system by hand in 4-decimal digit arithmetic with rounding, using Gaussian elimination without
    pivoting and backward substitution

    2. Relevant equations


    3. The attempt at a solution
    When they say 'without backward substitution', what am I supposed to do instead?
     
  2. jcsd
  3. Oct 27, 2014 #2

    Mark44

    Staff: Mentor

    I believe this means to completely reduce the matrix (reduced row-echelon form) so that the leading nonzero entry of each row is 1, and all entries above or below the 1 entry are 0.

    In other words, it should look something like this:
    $$\begin{bmatrix} 1 & 0 & ... & 0 & | & a \\ 0 & 1 & ... & 0 & | & b \\ . & . & ... & . &| . \\ 0 & 0 & ... & 1 & | & f \end{bmatrix}$$
     
    Last edited: Oct 27, 2014
  4. Oct 27, 2014 #3

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    If you use Gaussian elimination you cannot avoid using back substitution. However, if you use Gauss-Jordan elimination you avoid back substitution.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: System of linear equations
Loading...