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

Matlab question.please help me

  1. Feb 8, 2012 #1
    hi everyone
    I have a matlab question.
    I want find all of zeros below equation:
    c is light velocity,a,ω,εr,k0 are constant and known.
    t0 and tp are in terms of k.
    besseli and besselk are modified bessel functions of first and second type.
    in above equation all of quantities are known except k that k is zero of equation.
    i want to find zeros of "er*t0*besseli(1,tp*a)*besselk(0,t0*a)+tp*besselk(1,t0*a)*besseli(0,tp*a)=0",i.e i want find values of k.
    by using of solve command only one of the zeros are found.
    i can not use from fzero command,because there isn't guess point that is imaginary(k)=0.

    i don't now how find all of zeros in equation.:cry:
    this equation is dispersion relation of plasma.
    does anyone an idea for find zeros this equation?
    please help me!:cry:
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?