42nd Eötvös Competition 1938

------
1.  Show that a positive integer n is the sum of two squares iff 2n is the sum of two squares.
2.  Show that 1/n + 1/(n+1) + 1/(n+2) + ... + 1/n2 > 1 for integers n > 1.
3.  Show that for every acute-angled triangle ABC there is a point in space P such that (1) if Q is any point on the line BC, then AQ subtends an angle 90o at P, (2) if Q is any point on the line CA, then BQ subtends an angle 90o at P, and (3) if Q is any point on the line AB, then CQ subtends an angle 90o at P.

 

The original problems are in Hungarian. They are available on the KöMaL archive on the web. They are also available in English (with solutions) in: Andy Liu, Hungarian Problem Book III, 1929-1943, MAA 2001. ISBN 0883856441.

Eötvös home
 
(C) John Scholes
jscholes@kalva.demon.co.uk
6 January 2003
Last corrected/updated 3 Nov 03