Factoring Polynomials in Matlab

Let's find all roots of the polynomial

>> % polynomial = array of coefficients in matlab:
>> p = [1 0 0 0 5 7]; %  p(x) = x^5 + 5*x + 7
>> format long;       %  print double-precision
>> roots(p)           %  print out the roots of p(x)

ans =
  1.30051917307206 + 1.10944723819596i
  1.30051917307206 - 1.10944723819596i
 -0.75504792501755 + 1.27501061923774i
 -0.75504792501755 - 1.27501061923774i
 -1.09094249610903

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Order a Hardcopy of Mathematics of the DFT

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written by Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.