Cauchy's
inequality is named after
Augustin Cauchy
Let z
0 be a fixed
complex number. If a
function f is
analytic within and on a
circle centered at z
0 with
radius R, and the values on C of M
R are strictly <=
|f(z)|
f(n)(z0) <= (n!)(MR)/(r^n)
See also Liouville's Theorem.