Mathematics

Polynomial Roots

The roots function calculates the roots of a polynomial.

• r = roots(p)
  
  r =
        2.0946               
       -1.0473 +      1.1359i
       -1.0473 -      1.1359i
  

By convention, MATLAB stores roots in column vectors. The function poly returns to the polynomial coefficients.

• p2 = poly(r)
  
  p2 =
       1   8.8818e-16   -2   -5
  

poly and roots are inverse functions, up to ordering, scaling, and roundoff error.

Representing Polynomials

Characteristic Polynomials

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