Results 1 to 2 of 2

Math Help - Integration involving complex numbers

  1. #1
    Junior Member
    Joined
    Aug 2009
    Posts
    29

    Integration involving complex numbers

    I am trying to Integrate this equation

    \int\frac{dx}{x^2-6x+34}<br />

    i have tried to factorise the polynomial on the denominator and thus

    x=\frac {-b\pm\sqrt {b^2-4c}}{2}=3\pm5i<br />

    where b = -6, c = 34

    using my knowledge of complex functions this can be written as

    e^{3x} (c_1 cos 5x + c_2 sin 5x)<br />

    thus the integral can be written as

    \int\frac{dx}{e^{3x} (c_1 cos 5x + c_2 sin 5x)}

    not sure where to go now? any ideas?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Karl Harder View Post
    I am trying to Integrate this equation

    \int\frac{dx}{x^2-6x+34} <br />

    i have tried to factorise the polynomial on the denominator and thus

    x=\frac {-b\pm\sqrt {b^2-4c}}{2}=3\pm5i <br />

    where b = -6, c = 34

    using my knowledge of complex functions this can be written as

    e^{3x} (c_1 cos 5x + c_2 sin 5x) <br />

    thus the integral can be written as

    \int\frac{dx}{e^{3x} (c_1 cos 5x + c_2 sin 5x)}

    not sure where to go now? any ideas?
    x^2 - 6x + 34 = (x - 3)^2 + 25. This should suggest a standard form to you, especially if you first make the substitution u = x - 3.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Geometric Sum, involving complex numbers
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: June 4th 2011, 03:51 AM
  2. [SOLVED] A problem involving complex numbers in polar form
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: September 2nd 2010, 01:13 PM
  3. Simplifying an expression involving complex numbers.
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: May 20th 2010, 05:31 AM
  4. complex numbers involving demoivre
    Posted in the Algebra Forum
    Replies: 2
    Last Post: December 13th 2009, 01:41 AM
  5. equation involving complex numbers
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: March 29th 2009, 01:30 PM

Search Tags


/mathhelpforum @mathhelpforum