MathDB
Putnam 1977 A3

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April 7, 2022
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Problem Statement

Let u,fu,f and gg be functions, defined for all real numbers xx, such that u(x+1)+u(x1)2=f(x) and u(x+4)+u(x4)2=g(x).\frac{u(x+1)+u(x-1)}{2}=f(x) \text{ and } \frac{u(x+4)+u(x-4)}{2}=g(x). Determine u(x)u(x) in terms of ff and gg.