1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Find an effeciant way to deduce the roots of the equatioon

  1. Nov 10, 2012 #1
    1. The problem statement, all variables and given/known data

    Consider the fourth order equation x4 + 5x2 + 6 = 0.
    (a) Suggest an efficient way to find all roots of this equation.
    (b) List all the roots.


    2. Relevant equations



    3. The attempt at a solution

    -I plotted the graph.
    -I thought of iteration - Is that correct ? For that I have to change the form of the equation but then it is not given - Usually for iteration, they mention.
    -I thought of first derivative but what use is it going to be ?
     
  2. jcsd
  3. Nov 10, 2012 #2
    Can you find a suitable substitution??

    By the way, if you want to type an exponent such as x2. Then you can do this by

    Code (Text):

    [NOPARSE]x[SUP]2[/SUP][/NOPARSE]
     
     
  4. Nov 10, 2012 #3
    Yes, I got it with substitution !

    Thanks a lot ! And I will use the proper way for exponent next time.
     
  5. Nov 10, 2012 #4

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    Or: you can just write x^2 and x^4; these are also perfectly understandable.

    RGV
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook