View source for Gauss-Lucas theorem

{{TEX|done}}
''Gauss theorem''

Let $f(z)$ be a complex polynomial, i.e., $f(z)\in\mathbf C[z]$. Then the zeros of the derivative $f'(z)$ are inside the convex polygon spanned by the zeros of $f(z)$.

====References====
<table><TR><TD valign="top">[a1]</TD> <TD valign="top">  E. Hille,   "Analytic function theory" , '''1''' , Chelsea, reprint  (1982)  pp. 84</TD></TR><TR><TD valign="top">[a2]</TD> <TD valign="top">  P. Henrici,   "Applied and computational complex analysis" , '''I''' , Wiley, reprint  (1988)  pp. 463ff</TD></TR><TR><TD valign="top">[a3]</TD> <TD valign="top">  B.J. Lewin,   "Nullstellenverteilung ganzer Funktionen" , Akademie Verlag  (1962)  pp. 355</TD></TR></table>