Results 1 to 5 of 5

Math Help - multiple angle equations

  1. #1
    Member >_<SHY_GUY>_<'s Avatar
    Joined
    Jan 2008
    From
    CA
    Posts
    181

    Question multiple angle equations

    sin2x = \frac{-\sqrt3}{2}

    how to i solve this equation?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Nov 2009
    Posts
    277
    Thanks
    2

    First solve...

    First solve:

    <br /> <br />
sin y = \frac{-\sqrt3}{2}<br />

    Then solve

    <br /> <br />
y = 2x<br />
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member bigwave's Avatar
    Joined
    Nov 2009
    From
    honolulu
    Posts
    580
    sin2x = \frac{-\sqrt{3}}{2}
    2x = sin^{-1}(\frac{-\sqrt{3}}{2})
    x= \frac{1}{2}sin^{-1}(\frac{-\sqrt{3}}{2})  = -\frac{\pi}{3}

    check

    sin(2(\frac{-\pi}{3})) = \frac{-\sqrt{3}}{2}
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member >_<SHY_GUY>_<'s Avatar
    Joined
    Jan 2008
    From
    CA
    Posts
    181
    Quote Originally Posted by qmech View Post
    First solve:

    <br /> <br />
sin y = \frac{-\sqrt3}{2}<br />

    Then solve

    <br /> <br />
y = 2x<br />
    hopefully i did it right, but i got x = \frac{2\pi}{3}
    is there anything else i have to do?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Super Member bigwave's Avatar
    Joined
    Nov 2009
    From
    honolulu
    Posts
    580
    this is double angle formula...

    sin2X = 2sinXcosX

    to check x plug it back into the original equation....
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Multiple simultaneous equations
    Posted in the Advanced Algebra Forum
    Replies: 2
    Last Post: March 18th 2010, 06:57 AM
  2. Multiple Angle Formula Help
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: December 30th 2009, 10:07 AM
  3. Solving a trig multiple angle?
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: October 26th 2009, 09:15 PM
  4. Replies: 2
    Last Post: February 15th 2007, 11:16 PM
  5. Vector angle in multiple planes
    Posted in the Geometry Forum
    Replies: 2
    Last Post: January 23rd 2007, 08:59 PM

Search Tags


/mathhelpforum @mathhelpforum