Results 1 to 2 of 2

Math Help - Trigonometry problem

  1. #1
    Junior Member
    Joined
    Feb 2007
    Posts
    33

    Trigonometry problem

    cos²150 + cos²30


    I do not understand what you are supposed to do with the ² symbol following the tan, cos, sin things.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,818
    Thanks
    316
    Awards
    1
    Quote Originally Posted by Trentt View Post
    cos²150 + cos²30


    I do not understand what you are supposed to do with the ² symbol following the tan, cos, sin things.
    cos²150 = cos(150) * cos(150) = -cos(30) * -cos(30) = cos²30
    (ie. you are simply squaring the result of the cosine function.)

    So
    cos²150 + cos²30 = cos²30 + cos²30 = 2*cos²30 = 2*(sqrt{3}/2)² = 2*(sqrt{3}/2)*(sqrt{3}/2) = 2*(3/4) = 3/2

    -Dan
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. trigonometry problem
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 28th 2010, 12:06 AM
  2. trigonometry problem
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: December 24th 2009, 05:47 AM
  3. Trigonometry Problem
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: April 19th 2009, 08:55 AM
  4. trigonometry problem
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: January 9th 2009, 02:29 AM
  5. Trigonometry problem.
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: July 13th 2008, 08:17 PM

Search Tags


/mathhelpforum @mathhelpforum