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: Help me - A function satisfies the differential equation

  1. Feb 9, 2009 #1
    A function satisfies the differential equation:

    [tex]\frac{dy}{dt}= y^{4}-6y^{3}+5y^{2}[/tex]

    a. What are the constant solutions of the equation?
    b. For what values of y is y increasing?
    c. For what values of y is y decreasing?
  2. jcsd
  3. Feb 9, 2009 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    What are your thoughts on the problem? What have you attempted thus far?
  4. Feb 20, 2010 #3
    dy/dt=y'(t), its ur function or, simple, y(t), after integration.
    Last edited: Feb 20, 2010
  5. Feb 20, 2010 #4


    User Avatar
    Science Advisor

    Do you understand that this does NOT require that you actually solve the differential equation? It only requires that you solve an algebraic equation and two inequalities.
  6. Feb 20, 2010 #5
    i think it should be
    now integrate it
    we have
    constant solution mean y'(t)=0.
    mean no variation w.r.t "t".
    for what value of "t" is y increasing....
    and for what value of "t" is y decreasing.
    i think now u can handle it easily
    Last edited: Feb 20, 2010
  7. Feb 20, 2010 #6


    Staff: Mentor

    No, that's completely wrong. The DE equation is dy/dt = y4 - 6y3 + 5y2. If if were as you have it, this would be a different problem completely.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook