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Homework Help: Angles of a Vector on the Coordinate Plane

  1. Aug 23, 2010 #1
    1. The problem statement, all variables and given/known data

    This question is on my physics homework, I guess it could be posted elsewhere, but I'm not sure where. Here is the problem:

    Which of the following are the same as 18 degrees below the -x-axis? Choose all that apply:

    !!!The choices I selected are in red!!!

    A) 72 degrees left of the -y-axis
    B) 72 degrees right of the +y-axis

    C) 18 degrees right of the +y-axis
    D) 72 degrees below the -x-axis
    E) 18 degrees above the +x-axis
    F) 72 degrees above the +x-axis
    G) 18 degrees left of the -y-axis

    2. Relevant equations

    3. The attempt at a solution
    I got the answer wrong. I chose choice A. because I subtracted 90 degrees (-y-axis) from 18 giving me 72.

    I am thinking that I should change choice B. to C.and choice E. to F.? However, honestly I'm confused with my reasoning behind this. Nothing in my text speaks on this. Can anyone help? Thanks for your time.

    Also, if my question would be best answered in another place, please let me know. Like I said, this is from my physics homework....
  2. jcsd
  3. Aug 23, 2010 #2
    This seems quite simple.

    Try Drawing a graph to illustrate what it may look like.

    Then try to see which fits the descriptions best.

    I think http://www.studentforums.biz/index.php [Broken] site, will be able to give you a quicker reply, as they specialize in homework
    Last edited by a moderator: May 4, 2017
  4. Aug 24, 2010 #3
    Oooops I figured it out and I feel really silly lol.

    Thanks for the reply anways!
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