Page 2 of 2 FirstFirst 12
Results 16 to 18 of 18

Math Help - 1 Last question Guys

  1. #16
    MHF Contributor
    Joined
    Oct 2005
    From
    Earth
    Posts
    1,599
    Yes. That method looks good.

    You could just draw out the triangle I believe and not have to mess with a calculator, which may be what your teacher is getting at.
    Follow Math Help Forum on Facebook and Google+

  2. #17
    Super Member malaygoel's Avatar
    Joined
    May 2006
    From
    India
    Posts
    648
    Quote Originally Posted by topsquark View Post
    The problem with the double angle formulas is that the triangle where you have an angle of 2x doesn't have a simple relation to the triangle where you have an angle x. There is possibly a way to do it this way, but it is beyond my ken. Sometimes you just have to go algebraic instead of visual, I'm afraid.

    -Dan
    I think you are saying about this
    sinx=\sqrt{\frac{1-cos2x}{2}}
    cosx=\sqrt{\frac{1+cos2x}{2}}
    tanx=\sqrt{\frac{1-cos2x}{1+cos2x}}

    Keep Smiling
    Malay
    Follow Math Help Forum on Facebook and Google+

  3. #18
    Global Moderator

    Joined
    Nov 2005
    From
    New York City
    Posts
    10,616
    Thanks
    9
    Quote Originally Posted by malaygoel View Post
    I think you are saying about this
    sinx=\sqrt{\frac{1-cos2x}{2}}
    cosx=\sqrt{\frac{1+cos2x}{2}}
    tanx=\sqrt{\frac{1-cos2x}{1+cos2x}}

    Keep Smiling
    Malay
    In reality it should be (I mentioned this before a lot).
    For example for sine function,
    \sin x=\mbox{sgn } x \sqrt{\frac{1-\cos 2x}{2}}
    Where,
    \mbox{sgn } x=\left\{ \begin{array}{c} 1\mbox{ if }0+2\pi k\leq x\leq \pi+2\pi k\\ -1\mbox{ otherwise } \end{array} \right\}
    Follow Math Help Forum on Facebook and Google+

Page 2 of 2 FirstFirst 12

Similar Math Help Forum Discussions

  1. Replies: 4
    Last Post: March 10th 2011, 08:09 AM
  2. Ahhh tan! Easy question for you guys
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: November 9th 2009, 10:45 PM
  3. can you guys help me on a question
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: July 9th 2009, 04:11 AM
  4. we gotta problem here guys=("tough Question"
    Posted in the Algebra Forum
    Replies: 1
    Last Post: May 22nd 2008, 04:02 AM
  5. Replies: 15
    Last Post: April 29th 2007, 02:42 PM

Search Tags


/mathhelpforum @mathhelpforum