Results 1 to 3 of 3

Math Help - Finding the trig function

  1. #1
    Newbie
    Joined
    Jan 2013
    From
    achille
    Posts
    8

    Finding the trig function

    Hey guys, just to make sure I am on the right track here on this question: Find the remaining trigonometric functions of θ if cos(θ) = √3/2 and θ terminates in QI. Would the sine= 1?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Sep 2012
    From
    Australia
    Posts
    3,607
    Thanks
    591

    Re: Finding the trig function

    Hey goldbug78.

    Recall that sin^2 + cos^2 = 1 and that sin(x) >= 0 as well as cos(x) >= 0 in first quadrant.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,682
    Thanks
    614

    Re: Finding the trig function

    Hello, goldbug78!

    Find the remaining trigonometric functions of \theta
    if \cos\theta \,=\,\frac{\sqrt{3}}{2} and \theta terminates in quadrant 1.

    We are given: . \cos\theta \,=\,\frac{\sqrt{3}}{2} \,=\,\frac{adj}{hyp}

    Hence, \theta is in a right triangle with: adj = \sqrt{3},\:hyp = 2
    Code:
                              *
                          *   *
                   2  *       *
                  *           * x
              *  θ            *
          *   *   * _ *   *   *
                   √3
    Pythagorus: . x^2 + (\sqrt{3})^2 \:=\:2^2 \quad\Rightarrow\quad x^2 + 3 \:=\:4

    . . . . . . . . . . x^2 \:=\:1 \quad\Rightarrow\quad x \:=\:\pm1

    Since \theta is in quadrant 1, x \,=\,+1

    You have: . \begin{Bmatrix} opp &=& 1 \\ adj &=& \sqrt{3} \\ hyp &=& 2\end{Bmatrix}

    Go for it!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. finding the limit of a trig function
    Posted in the Calculus Forum
    Replies: 1
    Last Post: May 27th 2012, 12:06 PM
  2. Finding Values of the Trig Function
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: April 17th 2012, 03:04 AM
  3. Finding intersection of trig and non trig function
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: February 19th 2011, 06:53 PM
  4. Finding trig functions with one known function
    Posted in the Pre-Calculus Forum
    Replies: 5
    Last Post: September 9th 2009, 03:53 PM
  5. Finding a trig function given the value of another
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: April 23rd 2009, 10:30 PM

Search Tags


/mathhelpforum @mathhelpforum