Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Need help on an exercise from Gravitation(MTW)

  1. Jun 23, 2012 #1
    Hi, I'm working on exercise 9.13 of the "bible" Gravitation. The problem I have is how to derive the following equation:

    [itex]R_x(t)R_z(\psi)R_x(\theta)R_z(\phi) = R_z(\psi-tsin\psi cot\theta)R_x(\theta+tcos\psi)R_z(\phi+tsin\psi/sin\theta)[/itex]

    Where [itex]R_x(t)[/itex] denotes an infinitesimal rotation about x-axis, i.e. t<<1. [itex]R_z(\psi)R_x(\theta)R_z(\phi)[/itex] denote three consecutive FINITE angle rotations about z, x, and z axis, with Euler angles [itex]\psi[/itex], [itex]\theta[/itex] and [itex]\phi[/itex] respectively.

    Can anyone help me on this? Thanks!

    In case the latex doesn't work, I attach the equation below

    Attached Files:

    Last edited: Jun 23, 2012
  2. jcsd
  3. Sep 1, 2012 #2
    Since t<<1, you should solve this problem by doing approximation. And also, go from both sides of the equation.

    (I don't want to type more words only if you're still searching for help :tongue2:)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook