Results 1 to 2 of 2

Math Help - Proving

  1. #1
    Super Member
    Joined
    Dec 2009
    Posts
    755

    Proving

    Prove  <br />
\frac{1+tan^2A}{1-tan^2A}=sec2A<br />
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,678
    Thanks
    1499
    Quote Originally Posted by Punch View Post
    Prove  <br />
\frac{1+tan^2A}{1-tan^2A}=sec2A<br />
    \frac{1 + \tan^2{x}}{1 - \tan^2{x}} = \frac{1 + \frac{\sin^2{x}}{\cos^2{x}}}{1 - \frac{\sin^2{x}}{\cos^2{x}}}

     = \frac{\frac{\cos^2{x} + \sin^2{x}}{\cos^2{x}}}{\frac{\cos^2{x} - \sin^2{x}}{\cos^2{x}}}

     = \frac{\cos^2{x} + \sin^2{x}}{\cos^2{x} - \sin^2{x}}

     = \frac{1}{\cos^2{x} - \sin^2{x}}

     = \frac{1}{\cos{2x}}

     = \sec{2x}.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Proving (Q8B)
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: August 20th 2010, 09:14 AM
  2. Please me proving this.
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: March 27th 2010, 11:29 PM
  3. Proving
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: October 22nd 2009, 12:50 AM
  4. proving
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: August 6th 2009, 10:33 PM
  5. Proving an identity that's proving to be complex
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: July 21st 2009, 01:30 PM

Search Tags


/mathhelpforum @mathhelpforum