Results 1 to 2 of 2

Thread: proof of trig identity

  1. June 2nd 2009, 01:37 AM #1
    THSKluv
    THSKluv is offline
    Junior Member
    Joined
    Jun 2009
    Posts
    28

    proof of trig identity

    (sinA+sinB)/(cosA+cosB) + (cosA-cosB)/(sinA-sinB) = 0

    Prove the above trig identity

    THANKYOU !
    Follow Math Help Forum on Facebook and Google+
  2. June 2nd 2009, 01:56 AM #2
    alexmahone
    alexmahone is offline
    MHF Contributor alexmahone's Avatar
    Joined
    Oct 2008
    Posts
    1,071
    Thanks
    6
    \frac{sinA+sinB}{cosA+cosB} + \frac{cosA-cosB}{sinA-sinB}
    = \frac{sin ^2A-sin ^2B+cos^2A-cos^2B}{(cosA+cosB)(sinA-sinB)}

    ( sin^2\theta+cos ^2\theta=1)

    = \frac{1-1}{(cosA+cosB)(sinA-sinB)}
    = 0
    Last edited by alexmahone; June 2nd 2009 at 02:10 AM.
    Follow Math Help Forum on Facebook and Google+
« equation | Question on 3-d vectors »

Similar Math Help Forum Discussions

  1. Trig identity proof
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: February 5th 2010, 10:34 AM
  2. Help with a trig identity proof
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: January 26th 2010, 05:14 PM
  3. Proof of trig identity
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: December 12th 2009, 05:05 PM
  4. Another proof of trig identity =((
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: June 1st 2009, 03:34 AM
  5. Trig Identity Proof
    Posted in the Calculus Forum
    Replies: 5
    Last Post: February 25th 2008, 11:51 PM

Search Tags


/mathhelpforum @mathhelpforum