Given a univariate polynomial P(z) = z^3+az^2+bz+c whose zeros are the vertices of a triangle T in the complex plane, the isodynamic points of T are the zeros of the polynomial I(z) = (a^2-3b)z^2 + (ab-9c)z + b^2 - 3ac. Note that I(z) is a constant multiple of \mathrm{Discriminant}_u(nP(u) + (z-u)P'(u)), where n is the degree of P. This construction generalizes isodynamic points to polynomials of degree n\ge 3 in the sense that the zeros of the above discriminant are invariant under Möbius transformations. Here the expression nP(u) + (z-u)P'(u) is the polar derivative of P(u) with pole z.; .
