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: Vector Valued Funcations

  1. Oct 22, 2009 #1

    Can anyone please help me sove these problems:

    These are two different problems form different sections.

    1. Show that one arch of the cycloid r(t) = <t-sint, 1-cost> has length 8. Find the value of t in [0,2pi] where the speed is at a maximum.

    2. Find a parametization of the curve. The intersection of the surfaces z=x^2-y^2 and z=x^2+xy-1

  2. jcsd
  3. Oct 22, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Do you know the formulas for velocity, speed, and arc length?
  4. Oct 22, 2009 #3
    No, I don't.
  5. Oct 22, 2009 #4
    Then you should go and study and then comeback with some of your work. Nobody will do your homework for you.
  6. Oct 23, 2009 #5
    Actually this is no a homework question, its from a placement practice exam. So I didn't really know where to look for things. But, I think I have solved the 2nd. So Now just need help with 1st.

    The attempt at a solution
    2. z=x^2-y^2 and z=x^2+xy-1
    x^2-y^2 = x^2+xy-1
    x=(1/y) - y


    Set y=t

    Ans. r(t)=<(1/t)-t, t, (1/t)-t-t^2>

    1. I have no clue where to start. Although, I did find formulas for it.
    But can anyone please guide me on where to start?
  7. Oct 23, 2009 #6


    User Avatar
    Science Advisor

    This is a placement test?

    If you honestly have no idea how to approach such a problem, the last thing you want to do is to "trick" the people scoring the placement test to think that you do. The result would be that you wind up in a course where they expect you to already be able to do things you have no idea how to do!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook