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!

Linear Algebra - Cubic Equation from Given Points

  1. Sep 9, 2010 #1

    Cod

    User Avatar

    Linear Algebra -- Cubic Equation from Given Points

    1. The problem statement, all variables and given/known data

    Find the equation to the third polynomial that flows through the given points: (0,1); (1,0); (-1,0); (2, -15).

    2. Relevant equations

    f(t) = a + bt + ct^2 + dt^4

    Need to find a, b, c, and d.

    3. The attempt at a solution

    See attachment. When I plug my answer back in, it obviously doesn't work; however, I cannot figure out where I missed up the matrix.

    Any help is greatly appreciated.
     
    Last edited: Sep 9, 2010
  2. jcsd
  3. Sep 9, 2010 #2

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Re: Linear Algebra -- Cubic Equation from Given Points

    There is an error in the last column of your third matrix. You did not subtract 1 in the last column. It should be 0 2 4 8 -16, not -15.
     
  4. Sep 9, 2010 #3

    Cod

    User Avatar

    Re: Linear Algebra -- Cubic Equation from Given Points

    Thanks for catching that mistake. Found another algebra mistake in another matrix, but all in all, I figured everything out. Thanks again for pointing out my miscue.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Similar Discussions: Linear Algebra - Cubic Equation from Given Points
Loading...