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: Graphing vector functions help please urgent

  1. Jul 13, 2014 #1
    1. The problem statement, all variables and given/known data
    graph the curve C that is described by r and graph r′ at the indicated value of t.

    I've attached the actual question as a picture as a picture file

    2. Relevant equations


    3. The attempt at a solution

    I know x(t)= 2, y(t)=t , z(t)=4/1+t^2

    when x=0, r(t)=t+4/1+t^2

    when y=0, r(t)=2+4/1+t^2

    when z=0, r(t)=2+t

    Beyond this I have no idea what to do :( Any help would be very much appreciated, as this is quite urgent. Thank you in advance! (:

    Attached Files:

    • q23.PNG
      File size:
      3.6 KB
    Last edited: Jul 13, 2014
  2. jcsd
  3. Jul 13, 2014 #2

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    Where do you get
    [tex] z(t) = \frac{4}{1} + t^2 \, ?[/tex]
    I see
    [tex] z(t) = \frac{4}{1+t^2}.[/tex]
    Did you mean z(t) = 4/(1+t^2), using parentheses to make it read properly?

    Anyway, you are not allowed to set x = 0, because x(t) = 2 always. You are allowed to set y = 0, but only by setting t = 0 (because y(t) = t), etc. I cannot figure out what you are trying to do. The question asked you to plot ##\mathbf{r}(t)##, which is a curve in three dimensions; but since x = 2 always, it is really a plane-curve involving y and z, lying in the plane x = 2.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted