Bairstow’s method

Bairstow's method is an efficient algorithm for finding the roots of a polynomial of arbitrary degree. This method is more efficient as the others methods because it finds real and imaginary roots.
The method estimated the roots, using quadratic factors like:
x^(2 )- hx-d

Where the polynomial
p(x)=(x^2-hx-d) p_1 (x)

If x^(2 )- hx-d is not quadratic polynomial factor this would be expressed as follows:
p(x)=(x^2-hx-d) p_1 (x)+Ax+B

Where A and B are function of h and d’s, then looking for values of h and d where A and B are iqual to cero.
The use the newton-raphson`s method.