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: Trig transformation?

  1. Oct 11, 2007 #1
    1. The problem statement, all variables and given/known data

    A point with coordinates x and y is rotated in an anticlockwise direction through an angle z, so that its distance from the origin of the coordinate system remains constant. Show that the new x and y coordinates become

    xcosz - ysinz and xcosz + ysinz respectively.

    2. Relevant equations

    3. The attempt at a solution

    Well im looking for some advice on how to start this! The wording is confusing to me! To my mind surely if you rotate a point it will be exactly the same??? Any help would be supremely appretiated.
  2. jcsd
  3. Oct 11, 2007 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    By rotating a point, they mean it is rotated about the origin by a angle z. start by drawing a picture, show the x and y components at each location. Now study the pic until you can identify the relationships.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook