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!

Find the areas bounded by 4 equations

  1. Sep 10, 2007 #1

    tony873004

    User Avatar
    Science Advisor
    Gold Member

    1. The problem statement, all variables and given/known data
    I won't post the entire problem since I'm only stuck on one part of it. I need to find where y=cos x and y=sin 2x intersect.


    2. Relevant equations
    sin(x)=cos(x +- pi/2)

    [​IMG]

    3. The attempt at a solution

    cos x = sin 2x

    since sin(x)=cos(x +- pi/2), sin 2x = sin(x+pi/2), therefore, 2x=x+pi/2. This gives me 1/2 pi, which is 1 of the intersection points. And of course, any point 2pi away from this is another intersection point. But how do I find the other intersection point? The one that the graph shows to be at about 0.53.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 10, 2007 #2

    rock.freak667

    User Avatar
    Homework Helper

    sin2x =2sinxcosx (Double angle formula)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?