MathDB
Embedding in Q^n

Source: Iranian National Math Olympiad (Final exam) 2006

September 14, 2006
number theory proposednumber theory

Problem Statement

We mean a traingle in Qn\mathbb Q^{n}, 3 points that are not collinear in Qn\mathbb Q^{n} a) Suppose that ABCABC is triangle in Qn\mathbb Q^{n}. Prove that there is a triangle ABCA'B'C' in Q5\mathbb Q^{5} that BAC=BAC\angle B'A'C'=\angle BAC. b) Find a natural mm that for each traingle that can be embedded in Qn\mathbb Q^{n} it can be embedded in Qm\mathbb Q^{m}. c) Find a triangle that can be embedded in Qn\mathbb Q^{n} and no triangle similar to it can be embedded in Q3\mathbb Q^{3}. d) Find a natural mm' that for each traingle that can be embedded in Qn\mathbb Q^{n} then there is a triangle similar to it, that can be embedded in Qm\mathbb Q^{m}. You must prove the problem for m=9m=9 and m=6m'=6 to get complete mark. (Better results leads to additional mark.)