Entire function

In complex analysis, an entire function is a function that is analytic on the whole complex plane.

The main result governing the behavior of entire functions is Liouville's theorem, which states that a bounded entire function is constant. Here an entire function <math>f</math> is said to be bounded if there exists a constant <math>M</math> such that for all <math>z \in \mathbb C</math> the bound <math>f(z)<M</math> holds. Liouville's theorem yields a simple proof of the fundamental theorem of algebra: if <math>p(z)</math> were a polynomial with no roots in the complex plane, then one can prove that <math>1/p(z)</math> would be a bounded entire function, and thus constant.