  We provide a method for solving the roots of the general polynomial equation
a[n]*x^n+a[n-1]*x^(n-1)+..+a1*x+a0=0. To do so, we express x as a powerseries
of s, and calculate the first n-2 coefficients. We turn the polynomial equation
into a differential equation that has the roots as solutions. Then we express
the powerseries' coefficients in the first n-2 coefficients. Then the variable
s is set to a0. A free parameter is added to make the series convergent.
