Partial Fraction Decomposition

Metronome

Junior Member
Joined
Jun 12, 2018
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134
Heya, I have a few questions about partial fraction decomposition.

1) If the given denominator has only a repeated factor, i.e., p(s)/(q(s)^n) as opposed to p(s)/(r(s)q(s)^n), does that entail that the fraction cannot be further decomposed?

2) Is there a way to decompose fractions if the given denominator has factors raised to non-integer powers, i.e., s/((s - 3)(s + 1)^2.5)?

3) Is it normal to get incorrect answers if you don't fully factor the given denominator before decomposing? I don't have the exact fraction I was working, but it was something like p(s)/((s + 1)(s^2 - 4), and I wanted to decompose it into A/(s + 1) + (Bs + C)/(s^2 - 4) (to do cosh(2t) and sinh(2t) Inverse Laplace Transforms for the latter term). I kept getting the wrong answer until I broke up the s^2 - 4. Is this outcome expected when the denominator is only partially factored, or was is likely a calculation error?
 
1) No, not at all
2) I never thought of that but you should be able to do it by breaking off the fraction part
3)Doing something inefficiently should not yield the wrong results. It is possible that you do not get the desired form that you want but never will you get wrong answers.
 
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