Results 1 to 4 of 4
Like Tree1Thanks
  • 1 Post By jakncoke

Math Help - Cos2θ to sinθ? Identity conversions

  1. #1
    Newbie
    Joined
    Nov 2012
    From
    ga
    Posts
    9

    Cos2θ to sinθ? Identity conversions

    How to find cos2θ if sinθ = 2?

    How to find cosθ if sin2θ = 3?

    Both lie in quadrant I. I'm unsure how to convert from one identity to the other ...
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member jakncoke's Avatar
    Joined
    May 2010
    Posts
    387
    Thanks
    80

    Re: Cos2θ to sinθ? Identity conversions

    How can  sin(\theta) = 2 if its maximum value is 1.
    Thanks from topsquark
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454

    Re: Cos2θ to sinθ? Identity conversions

    In this post ...

    Double Angle Equations!

    ...you were requested to post specific problems rather than cryptic references to double angle problems. Now it seems you're making up stuff, because you really don't know what you're doing.

    Post a specific problem from a text or as given by your instructor.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,939
    Thanks
    338
    Awards
    1

    Re: Cos2θ to sinθ? Identity conversions

    Quote Originally Posted by whittwhitt View Post
    How to find cos2θ if sinθ = 2?

    How to find cosθ if sin2θ = 3?

    Both lie in quadrant I.
    Yes. Impossible. -1 \leq sin(\theta) \leq 1. For any angle in any quadrant.

    Quote Originally Posted by whittwhitt View Post
    I'm unsure how to convert from one identity to the other ...
    You have now got several references to the double angle formulas. Please use them and show us what you've got.

    But please let us know what the actual problem statements are. You have been asked to clarify a question before.

    -Dan
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 4
    Last Post: July 16th 2011, 02:31 PM
  2. Finding cos2*theta
    Posted in the Trigonometry Forum
    Replies: 7
    Last Post: June 26th 2011, 08:03 AM
  3. Solve sin4(theta) = cos2(theta)
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: December 8th 2008, 10:23 AM
  4. Conversions Again
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: September 10th 2008, 05:17 PM
  5. Conversions?
    Posted in the Math Topics Forum
    Replies: 6
    Last Post: September 9th 2008, 06:36 PM

Search Tags


/mathhelpforum @mathhelpforum