1. Not finding help here? Sign up for a free 30min 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!

Simple trigonometry check

  1. Nov 5, 2009 #1
    1. The problem statement, all variables and given/known data
    a = 1/sqrt(29) * (-2*sint, 0, -2*cost)
    length of a is?

    2. Relevant equations



    3. The attempt at a solution
    ignoring 0, we have sqrt{[(-2*sint)/sqrt(29)]^2 + [(-2*cost)/sqrt(29)]^2}. I get 2/sqrt(29) but answer is [2*sqrt(2)]/sqrt(29). Can anyone do this step by step and show me please..
     
  2. jcsd
  3. Nov 5, 2009 #2

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    No need to. You answer is correct. [itex]2\sqrt{2}/\sqrt{29}[/itex] would be [itex]\sqrt{4+ 4}/\sqrt{29}[/itex] but [itex]4sin^2(t)+ 4cos^2(t)= 4[/itex] not 4+ 4.
     
  4. Nov 5, 2009 #3
    hmm so solution must be wrong.. I wonder why no one pointed it out tho
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Simple trigonometry check
Loading...