Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Doubts on vector norm!

  1. Apr 12, 2012 #1
    Hi guys

    Assume F to be a square matrix, say 3 by 3. Now I want to find a vector q (3 by 1) to meet the requirement that norm(F*q)=1. How can I find it? What is the solution in general?

    THanks in advance!!
    Jo
     
  2. jcsd
  3. Apr 12, 2012 #2


    Let v be any vector s.t. [itex]Fv\neq 0[/itex] and let [itex]q:=\frac{v}{||Fv||}[/itex]

    DonAntonio
     
  4. Apr 12, 2012 #3
    a b c * [k l m]' = [ak+bl+cm, ek+fl+gm, hk+il+jm]'
    e f g
    h i j

    So we need (k, l , m) such that:
    (ak+bl+cm)^2+ (ek+fl+gm)^2 + (hk+il+jm)^2 = 1

    Answer, first chose l = m = 0, so we need:
    a^2 + e^2 + h^2 = 1/k^2

    or k = sqrt (1/(a^2 + e^2 + h^2))
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Doubts on vector norm!
Loading...