Results 1 to 3 of 3

Math Help - proving identities

  1. #1
    Newbie
    Joined
    Nov 2009
    Posts
    1

    proving identities

    please i need help with this problem.

    cosB/1-tanB + sinB/1-cotB = sinB + cosB

    how can i prove this identity?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,621
    Thanks
    426
    Quote Originally Posted by Cooks View Post
    please i need help with this problem.

    cosB/1-tanB + sinB/1-cotB = sinB + cosB

    how can i prove this identity?
    working on the left side ...

    \frac{\cos{\beta}}{\cos{\beta}} \cdot \frac{\cos{\beta}}{1-\tan{\beta}} + \frac{\sin{\beta}}{\sin{\beta}} \cdot \frac{\sin{\beta}}{1-\cot{\beta}}

    \frac{\cos^2{\beta}}{\cos{\beta} - \sin{\beta}} + \frac{\sin^2{\beta}}{\sin{\beta}-\cos{\beta}}

    \frac{\cos^2{\beta}}{\cos{\beta} - \sin{\beta}} - \frac{\sin^2{\beta}}{\cos{\beta} - \sin{\beta}}

    \frac{\cos^2{\beta}-\sin^2{\beta}}{\cos{\beta} - \sin{\beta}}

    factor the numerator and finish it up ...
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member mrmohamed's Avatar
    Joined
    Dec 2009
    From
    Egypt
    Posts
    43

    Lightbulb

    Quote Originally Posted by Cooks View Post
    please i need help with this problem.

    cosB/1-tanB + sinB/1-cotB = sinB + cosB

    how can i prove this identity?
    hi all


    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Proving Identities
    Posted in the Discrete Math Forum
    Replies: 3
    Last Post: September 14th 2010, 07:16 AM
  2. Replies: 6
    Last Post: June 22nd 2010, 11:59 PM
  3. Proving Identities
    Posted in the Calculus Forum
    Replies: 10
    Last Post: October 28th 2009, 01:33 PM
  4. Proving identities
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: July 9th 2009, 07:50 PM
  5. Proving identities
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: December 31st 2008, 11:37 PM

Search Tags


/mathhelpforum @mathhelpforum