2002 IMO Problems/Problem 5

Problem

Find all functions $f:\Bbb{R}\to \Bbb{R}$ such that

\[(f(x)+f(z))(f(y)+f(t))=f(xy-zt)+f(xt+yz)\]

for all real numbers $x,y,z,t$.

Solution

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See Also

2002 IMO (Problems) • Resources
Preceded by
Problem 4
1 2 3 4 5 6 Followed by
Problem 6
All IMO Problems and Solutions