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: Elliptical motion

  1. Feb 14, 2010 #1


    User Avatar

    1. The problem statement, all variables and given/known data

    Hi!, can anybody help me with this problem?

    Proof that the position vector r(t) = A cos [tex]\omega[/tex]t i + B sin ([tex]\omega[/tex]t + [tex]\alpha[/tex]) moves on an ellipse.

    I understand that the parametric equation for an ellipse is x=a cos t & y=b sin t, but I just can't find any trigonometric identity that helps me. Do you know any math trick that could help me?
  2. jcsd
  3. Feb 14, 2010 #2


    User Avatar
    Homework Helper

    x=a cos t, y=b sin t is only for a canonical ellipse. If you find the general parametric equation for an ellipse, you'll see that your equation fits perfectly.
  4. Feb 15, 2010 #3


    User Avatar

    I understood what you say, but the only thing I could see was that the ellipse is rotated, but I still don't know how to prove the statement
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook