1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Factoring a fraction

  1. Feb 27, 2006 #1
    how do I make:

    20(x + 20) / ((x+10)^2 + 400)

    into a fraction like (x-a)(x-b)....etc / (x-c)(x-d)....etc

    where a b c d are constants. The 400 is really stumping me.
  2. jcsd
  3. Feb 27, 2006 #2


    User Avatar
    Science Advisor
    Homework Helper

    It's impossible if a, b, c, d, ... have to be real numbers. If they can be complex, then you can do it. Well, actually, no you technically can't do it because of the 20, but you can come closer to your goal.
  4. Feb 27, 2006 #3
    I assume you are asking this to find the inverse Laplace transform for your circuit problems. What you don't see is that the form is already in the form that is useful to be inverted.

    [tex]Y(s) = 20 \frac {s+20}{(s+10)^2 + 400} = 20 \frac {s + 10 + 10}{(s+10)^2 + 400} = 20 \bigg[ \frac {s+10}{(s+10)^2+400} + \frac {10}{(s+10)^2 + 400}\bigg][/tex]

    Now look up the Laplace transforms of cosines and sines.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?