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!

Numerical analysis

  1. Dec 3, 2007 #1
    1. The problem statement, all variables and given/known data
    take the rational function R(x)=(a+bx)\(c+dx). What does the interpolatory requirment R(xi)=yi, i=1,2,3,4 amount to? under what conditions can you find coefficients? uniquely?

    2. Relevant equations

    3. The attempt at a solution
    Let y=[y1,y2,y3,y4] and v=[a,b,c,d] and let A be an 4x4 matrix. then I want to try to write this as Av=y and the solution would would exist and be unique when A is invertible. so I write a+bxi=(c+dxi)yi. then I can write a+bxi-cyi-d(xi)(yi)=0 but this wont give me the solution because we could just write a=b=c=d=0 for any x and y. since I know yi and xi I could have a+bxi-cyi = d(xi)(yi) and set up the matrix that way but it still won't give me what I want since I wouldn't be able to find d. Am I on the right track? any suggestions on where to go from here? thanks
  2. jcsd
  3. Dec 3, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper

    In A you have 16 matrix elements, but Av = y corresponds to only 4 equations. You need 12 more equations for a unique solution.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Numerical analysis
  1. Numerical Analysis (Replies: 2)

  2. Numerical analysis (Replies: 5)

  3. Numerical analysis (Replies: 2)

  4. Numerical Analysis (Replies: 3)