Results 1 to 2 of 2

Math Help - How do I solve this trig equation??

  1. #1
    Newbie
    Joined
    Nov 2009
    Posts
    4

    How do I solve this trig equation??

    Find the EXACT solutions of the given equation in the interval [0,2π). If there is more than one answer, enter them in a list separated by commas. Decimal approximations and symbolic trigonometric expressions such as arctan(5) will be marked incorrect.

    2sin^2(x)-5sin(x)+2=0

    Where do I even begin on this? I'm lost and my professor has stopped coming because of an injury and I have a test Wendesday. I'd appreciate all the help I can get! Thanks so much in advance.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Amer's Avatar
    Joined
    May 2009
    From
    Jordan
    Posts
    1,093
    Quote Originally Posted by dcowboys107 View Post
    Find the EXACT solutions of the given equation in the interval [0,2π). If there is more than one answer, enter them in a list separated by commas. Decimal approximations and symbolic trigonometric expressions such as arctan(5) will be marked incorrect.

    2sin^2(x)-5sin(x)+2=0

    Where do I even begin on this? I'm lost and my professor has stopped coming because of an injury and I have a test Wendesday. I'd appreciate all the help I can get! Thanks so much in advance.

    ok let u= sin x

    2u^2 - 5 u +2 = 0

    (2u-1)(u-2)

    u= \frac{1}{2} \Rightarrow \sin x  =\frac{1}{2} \Rightarrow x=\frac{\pi}{6} , x=\frac{5\pi}{6}



    u-2 = 0 \Rightarrow \sin x = 2 and this can't be true since sin x is bounded by -1 and 1
    Last edited by Amer; November 16th 2009 at 07:43 PM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Compute Trig Function Values, Solve Trig Equation
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: September 8th 2011, 07:00 PM
  2. How to solve this trig equation!
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: November 15th 2010, 07:31 PM
  3. solve this trig equation
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 6th 2010, 04:42 PM
  4. solve trig equation help.
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: November 20th 2009, 06:11 AM
  5. Solve this trig equation
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: September 18th 2009, 02:35 AM

Search Tags


/mathhelpforum @mathhelpforum