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- 06:04, 31 July 2010 (diff | hist) . . (+299) . . N 1986 IMO Problems/Problem 5 (Created page with 'Find all (if any) functions <math>f</math> taking the non-negative reals onto the non-negative reals, such that (a) <math>f(xf(y))f(y) = f(x+y)</math> for all non-negative <math…')
