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!

:trigonometric identity question

  1. Jan 12, 2010 #1
    URGENT:trigonometric identity question

    1. The problem statement, all variables and given/known data
    tan2x+cos2x+sin2x=sec2x
    *the 2 stands for squared since I dont know how to make the squared symbol appear on a compter



    2. Relevant equations
    http://www.analyzemath.com/Trigonometry_2/Trigonometric_identities.html
    stuff from this website and more


    3. The attempt at a solution
    (sin2x+cos2x(cos2x)+sin2xcos2x)/cos2x

    1+cos2x+sin2xcos2x/cos2x

    1+sin2xcos2x

    any help is appreciated as I have been at this for over an hour and cant figure it out and it needs to be done soon
     
  2. jcsd
  3. Jan 12, 2010 #2

    rock.freak667

    User Avatar
    Homework Helper

  4. Jan 12, 2010 #3
    Re: URGENT:trigonometric identity question

    take note of this identities:
    tan²x=sec²x-1
    cos²x+sin²x=1
     
  5. Jan 12, 2010 #4
    Re: URGENT:trigonometric identity question

    Or you can work from "base principles" replacing sin x with opposite over hypotenuse, cos x with adjacent over hypotenuse et cetera :rolleyes:
     
  6. Jan 12, 2010 #5

    Mark44

    Staff: Mentor

    Re: URGENT:trigonometric identity question

    A better idea would be to replace tan2(x) with (sin2(x))/(cos2(x)) and sec2(x) with 1/(cos2(x)). That way all your quantities would be in terms of powers of sinx and cosx.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: :trigonometric identity question
  1. Trigonometric Identity (Replies: 8)

  2. Trigonometric identity (Replies: 1)

  3. Trigonometric identity (Replies: 7)

  4. Trigonometric Identity (Replies: 1)

Loading...