Is an Entire Function Satisfying f(z+i)=f(z) and f(z+1)=f(z) Constant?

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SUMMARY

An entire function that satisfies the conditions f(z+i)=f(z) and f(z+1)=f(z) must be constant. This conclusion is derived from the application of Liouville's theorem, which states that a bounded entire function is constant. The function values are determined by their values on a compact set, and since the continuous image of a compact set is bounded, the function must be bounded. Therefore, by Liouville's theorem, the function cannot be anything other than constant.

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Homework Statement


if an entire function satisfies f(z+i)=f(z) and f(z+1)=f(z), must the function be constant?


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The Attempt at a Solution


It's true that f(0) = f(k) = f(ik) where k is an integer. I'm wondering whether I can apply Liouville's theorem into this somehow or if it's not constant at all on how to construct a counterexample.
 
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Hmm...well I think you can show that all of the function values are determined by the function values on a certain compact set. Since the continuous image of a compact set is bounded, the function must be bounded and so you can apply Liouville's theorem.
 

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