Results 1 to 2 of 2

Math Help - Prove the identity

  1. #1
    Newbie
    Joined
    Aug 2009
    Posts
    3

    Prove the identity

    4sin2xcos2x=2sin4x

    6cot^22x-csc^22x=6cos^32x
    Follow Math Help Forum on Facebook and Google+

  2. #2
    -1
    e^(i*pi)'s Avatar
    Joined
    Feb 2009
    From
    West Midlands, England
    Posts
    3,053
    Thanks
    1
    Quote Originally Posted by Yuroichi View Post
    4sin2xcos2x=2sin4x

    6cot^22x-csc^22x=6cos^32x
    1. Use the double angle identity sin(2u) = 2sin(u)cos(u).
    In this case u=2x

    2. This is not an identity - try x = 1.25\pi

    \frac{6cos^2(2x)-1}{sin^2(2x)}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. prove identity help!
    Posted in the Trigonometry Forum
    Replies: 7
    Last Post: December 2nd 2010, 10:00 AM
  2. prove the identity
    Posted in the Algebra Forum
    Replies: 3
    Last Post: June 7th 2010, 05:03 PM
  3. Prove this identity?
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: April 5th 2010, 05:29 PM
  4. Prove that each of the following is an identity
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: April 18th 2009, 02:39 PM
  5. Prove the Identity
    Posted in the Trigonometry Forum
    Replies: 10
    Last Post: February 25th 2008, 05:29 PM

Search Tags


/mathhelpforum @mathhelpforum