NETMaths

Is this true?

A bounded holomorphic function on an unbounded domain is constant

No — it is false.

The counterexample

f(z) = eᶻ on {Re z < 0}

|eᶻ| < 1 there, but f is not constant. Liouville needs the whole plane.

The kind of mistake this is

Standard counterexample

There is a canonical object that settles this. Recognising it is the whole question.

Drill statements like this

Others that fail the same way

From Cauchy TheoryLiouville, Morera, maximum modulus principle

ShareWhatsAppTelegram