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!

Qualative look at diffy Q

  1. Oct 23, 2013 #1
    1. The problem statement, all variables and given/known data

    The funciton with the given graph is a solution of one of the following differential equations. Decide which one is correct and justify your answer.

    So does anyone know how I can draw this so you guys can see? Like a web site? The graph is non linear it is increasing up to what looks like a y intercept of 1 then it decreases non linearly in the first quadrant. It still increases for a tiny bit after is crosses the intercept.

    2. Relevant equations

    A) y ' = 1+xy B) y' = -2xy C. y' = 1-2xy

    3. The attempt at a solution

    I say it is C because that eq would have a y int of 1 which is what my graph looks like. and would have a neg slope in the first quadrant. But I don't know.


    Anyone know a site so I can draw it so you can see?
     
  2. jcsd
  3. Oct 23, 2013 #2

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    It would? Why?
     
  4. Oct 24, 2013 #3

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    I think you are misunderstanding what is given. The graph of y' would have a "y intercept of 1" but the graph you are given is of y, not y'. In (c), if x and y are both between 0 and 1/4 (so in the first quadrant) 1-2xy> 0 so the graph of y is increasing.


    You can download, for free, a very nice graphing program at http://www.padowan.dk/
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Qualative look at diffy Q
  1. Really Messy Diffy Q (Replies: 1)

  2. Another Messy Diffy Q (Replies: 1)

  3. Basic Diffy Q (Replies: 1)

  4. Second order diffy Q (Replies: 5)

  5. Linear diffy q (Replies: 5)

Loading...