Problem A. 420. (February 2007)
A. 420. Find all functions such that |f(x)-f(y)|
|x-y| for all x,y>0 and there exist positive constants a, b, c satisfying
for all x.
(Proposed by Edgár Dobribán, Cluj-Napoca (Romania))
(5 pont)
Deadline expired on March 19, 2007.
Statistics:
12 students sent a solution. 5 points: Dobribán Edgár, Gyenizse Gergő, Hujter Bálint, Kisfaludi-Bak Sándor, Kónya 495 Gábor, Lovász László Miklós, Nagy 224 Csaba, Nagy 235 János, Nagy 314 Dániel, Tomon István. 2 points: 1 student. 0 point: 1 student.
Problems in Mathematics of KöMaL, February 2007