MathDB
Romania District Olympiad 2002 - Grade XI

Source:

March 18, 2011
linear algebramatrixfunctionlinear algebra unsolved

Problem Statement

a)Find a matrix AM3(C)A\in \mathcal{M}_3(\mathbb{C}) such that A2O3A^2\neq O_3 and A3=O3A^3=O_3. b)Let n,p{2,3}n,p\in\{2,3\}. Prove that if there is bijective function f:Mn(C)Mp(C)f:\mathcal{M}_n(\mathbb{C})\rightarrow \mathcal{M}_p(\mathbb{C}) such that f(XY)=f(X)f(Y), X,YMn(C)f(XY)=f(X)f(Y),\ \forall X,Y\in \mathcal{M}_n(\mathbb{C}), then n=pn=p.
Ion Savu