Mathematical and Physical Journal
for High Schools
Issued by the MATFUND Foundation
 Already signed up? New to KöMaL?

# Problem A. 644. (May 2015)

A. 644. Let $\displaystyle f(x,y)$ be a polynomial with two variables and integer coefficients such that $\displaystyle f$ is constant neither in $\displaystyle x$- nor in $\displaystyle y$-direction. Prove that $\displaystyle \max_{a,b\in[-2,2]}\big|f(a,b)\big|\ge4$.

Based on the idea of Tamás Erdélyi, College Station, Texas

(5 pont)

Deadline expired on June 10, 2015.

### Statistics:

 1 student sent a solution. 5 points: Williams Kada.

Problems in Mathematics of KöMaL, May 2015