The Weierstrass-Durand-Kerner method

This is a method for finding all the roots of a polynomial simultaneously, by applying a sort of Newton-Raphson method. It gets its name from everybody associated wth it: Weierstrass published a version of the algorithm in 1891, and then rediscovered (independently) by Durand in 1960 and Kerner in 1966, as you can see at its Wikipedia page . It&rsquo;s easier to describe by an example: \[ x^4 -…