Paper 4, Section I, G

Complex Analysis
Part IB, 2014

Let ff be an entire function. State Cauchy's Integral Formula, relating the nnth derivative of ff at a point zz with the values of ff on a circle around zz.

State Liouville's Theorem, and deduce it from Cauchy's Integral Formula.

Let ff be an entire function, and suppose that for some kk we have that f(z)zk|f(z)| \leqslant|z|^{k} for all zz. Prove that ff is a polynomial.