Results 1 to 2 of 2

Math Help - Rationalizing the denominator and expressing a fraction as a surd

  1. #1
    Member
    Joined
    Jul 2007
    Posts
    147

    Rationalizing the denominator and expressing a fraction as a surd

    I'm sorry about the stupid questions, I just don't understand this.

    Express these in surd form and rationalize the denominators



    a)
    \frac{1}{1+cos45}




    Thank you so much!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by Coach View Post
    I'm sorry about the stupid questions, I just don't understand this.

    express these in surd form and rationalize the denominators



    a)
    \frac{1}{1+cos45}
    you should know that \cos 45^{\circ} = \frac {\sqrt {2}}{2}

    so, \frac {1}{1 + \cos 45} = \frac {1}{1 + \frac {\sqrt {2}}{2}}

    = \frac {1}{\frac {2 + \sqrt {2}}{2}}

    = \frac {2}{2 + \sqrt {2}}

    Now we need to rationalize this. I don't want to do all the work for you, so i'll tell you what to do.

    multiply by the conjugate of the base ( 2 - \sqrt {2}) over itself, and simplify
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Rationalizing Denominator
    Posted in the Calculus Forum
    Replies: 2
    Last Post: July 21st 2011, 11:59 AM
  2. Rationalizing the Denominator
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 2nd 2009, 08:13 AM
  3. Rationalizing the Denominator
    Posted in the Algebra Forum
    Replies: 2
    Last Post: January 23rd 2009, 10:43 PM
  4. Rationalizing the Denominator
    Posted in the Algebra Forum
    Replies: 9
    Last Post: September 10th 2008, 02:03 PM
  5. Rationalizing a Denominator
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: December 14th 2007, 08:44 AM

Search Tags


/mathhelpforum @mathhelpforum