Results 1 to 2 of 2

Math Help - Trigonometric equations

  1. #1
    Junior Member
    Joined
    Jan 2010
    Posts
    43

    Exclamation Trigonometric equations

    Been having problem with a few questions from my review for solving trig equations

     <br />
Cos2X(Sin2x-1)=0<br />

    and

     <br />
2Cos^2x-cosx-1=0<br />
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,623
    Thanks
    428
    Quote Originally Posted by nightrider456 View Post
    Been having problem with a few questions from my review for solving trig equations

     <br />
Cos2X(Sin2x-1)=0<br />

    and

     <br />
2Cos^2x-cosx-1=0<br />
    \cos(2x)[\sin(2x)-1]=0

    set each factor equal to 0 and solve ...

    \cos(2x) = 0

    2x = \frac{\pi}{2} , 2x = \frac{3\pi}{2} , ...

    \sin(2x) = 1

    2x = \frac{\pi}{2} , 2x = \frac{5\pi}{2} , ...


    2\cos^2{x}-\cos{x}-1=0

    (2\cos{x} + 1)(\cos{x} - 1) = 0

    same drill ... set each factor equal to 0 and solve.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Trigonometric equations
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: August 6th 2010, 10:21 AM
  2. Trigonometric Equations
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: November 5th 2009, 08:30 PM
  3. Trigonometric Equations Help!!!!!
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: January 25th 2009, 02:12 PM
  4. Trigonometric Equations
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: September 1st 2008, 09:09 PM
  5. Trigonometric equations?
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: June 22nd 2008, 09:58 AM

Search Tags


/mathhelpforum @mathhelpforum