7

Part of 2006 India Regional Mathematical Olympiad

Problems(1)

Problem 7 of RMO 2006 (Regional Mathematical Olympiad-India)

Source: Functional Equation

X

be the set of all positive integers greater than or equal to

8

f: X\rightarrow X

be a function such that f(x\plus{}y)\equal{}f(xy) for all

x\ge 4, y\ge 4 .

if f(8)\equal{}9, determine

f(9) .

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