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!

Parametric equation

  1. Jun 19, 2014 #1
    t^2,t^4,t^6

    Trying to graph this

    I have the traces
    x=y^2 for x>=0 in xy
    Also x=z^3 for z>=0 in xz
    And z=y^(3/2) for y>=0 in yz

    Parametricplot3d in mathematics does nothing to get a picture for this graph and drawing is proofing difficult
    In general what is the best way to plot these when it's not obvious plug in for t?
     
    Last edited: Jun 19, 2014
  2. jcsd
  3. Jun 19, 2014 #2

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    It's not clear what you are trying to do.

    Is your function f(x,y,z) = (t^2, t^4, t^6) perhaps? Or something else?
     
  4. Jun 20, 2014 #3
    Yes that is the function of x y z
    I am trying to graph it
     
  5. Jun 20, 2014 #4

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    I think you mean, vectorially, r(t) = (t^2, t^4, t^6), i.e. x = t^2 etc..
    But from the OP,
    suggests r(t) = (t^6, t^4, t^2).
    It depends what range of t you want to sketch it for.
    It's kind of hard to sketch 3D curves. What exactly have you been asked to do?
     
  6. Jun 20, 2014 #5
    Sketch the curve
    mathematica doesn't help
     
    Last edited: Jun 20, 2014
  7. Jun 20, 2014 #6
    The book asks for a sketch I assume there is a reasonable way
    Plot t values?
     
  8. Jun 20, 2014 #7
    Is this what you are looking for?
    Code (Text):
    ParametricPlot3D[{t^2, t^4, t^6}, {t, 0, 1}]
    If it isn't then perhaps you can explain what is incorrect about that.
     
  9. Jun 20, 2014 #8
    Is gives a line I am under the impression that the graph is a surface
    What's throwing me off is the book taking the trace in each plane
    Sint,cost,t cylinder along z
     
  10. Jun 20, 2014 #9

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    No: the point-set you describe is a one-dimensional object = a curve in 3d. If you wanted a surface you would need two independent variables, so you would need to have something like three functions x(u,v), y(u,v), z(u,v) in two variables u and v.
     
  11. Jun 20, 2014 #10
    In cost,sint,t
    z for all real isn't a cylinder?
     
  12. Jun 21, 2014 #11
    Nope.

    Code (Text):
    ParametricPlot3D[{Cos[t], Sin[t], t}, {t, 0, 4 Pi}]
    It is perhaps difficult to get a really good 3D view of it, but try from different angles and guess what it is.
     
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: Parametric equation
  1. Parametric equations (Replies: 4)

  2. Parametric equations (Replies: 1)

  3. Parametric Equations (Replies: 6)

  4. Parametric Equation (Replies: 3)

Loading...