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!

Trig functions squared

  1. Jan 10, 2009 #1
    1. The problem statement, all variables and given/known data
    cos2 0 = 1/2 (0 for angle)


    2. Relevant equations



    3. The attempt at a solution
    I've never seen cos, sin, or tan to the power of anything before what do i do with the power?
     
  2. jcsd
  3. Jan 10, 2009 #2

    rock.freak667

    User Avatar
    Homework Helper

    What you could do is use an the identity [itex]cos 2\theta=2cos^2\theta-1[/itex]

    OR

    put [itex]cos\theta= \pm \frac{1}{\sqrt{2}}[/itex] and then just solve [itex]cos\theta= \frac{1}{\sqrt{2}}[/itex] and [itex]cos\theta= \frac{-1}{\sqrt{2}}[/itex]
     
  4. Jan 10, 2009 #3
    Perhaps you are unfamiliar with the notation: [tex]\cos^2{\theta}[/tex] means [tex](\cos{\theta})^2[/tex].
     
  5. Jan 10, 2009 #4

    Delphi51

    User Avatar
    Homework Helper

    You don't say what you are supposed to do with it!
    You could find the value of the angle easily by taking the square root of both sides to get
    cos \\theta =
    on the left.
     
  6. Jan 10, 2009 #5

    Delphi51

    User Avatar
    Homework Helper

    You don't say what you are supposed to find! Maybe the angle?
    If you take the square root of both sides you'll get

    cos 0
    on the left

    Can someone tell me how to get a "theta" in this forum?
     
  7. Jan 10, 2009 #6
    You can just hit quote and see how others have done it but if you use [ tex] ... [/ tex] tags (obviously without spaces) then to get the symbol theta you would just use \theta
     
  8. Jan 10, 2009 #7

    Delphi51

    User Avatar
    Homework Helper

    Thanks! Hope this works . . .
    cos [tex]\theta[/tex]
     
  9. Jan 10, 2009 #8
    Instead of doing cos[tex]\theta[/tex]. I think this looks much nicer:

    [tex]\cos(\theta)[/tex]

    You can click on what you are trying to see the TeX "code" for and a box will open telling you the "code"
     
  10. Jan 10, 2009 #9

    Delphi51

    User Avatar
    Homework Helper

    Thanks again, NoMoreExams. I actually saw that click on trick before, but it didn't show the [ tex] so I couldn't get it to work.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Trig functions squared
  1. Trig Function (Replies: 2)

  2. Trig Functions . (Replies: 16)

  3. Trig function help (Replies: 14)

Loading...