1. Let be a class of functions from to that satisfies: (i) The functions and are in (ii) If and are in the functions and are in (iii) If and are in and for all then the function is in Prove that if an… more →
Beni Bogoşel's blogwrote 4 months ago: 1. Let be a class of functions from to that satisfies: (i) The functions and are in (ii) If and are … more →
wrote 4 months ago: 1. Let be real numbers in the open interval Show that there exist distinct indices such that are the … more →
wrote 5 months ago: Let be a convex polygon which has no two sides which are parallel. For each side consider the vertex … more →
wrote 6 months ago: Prove that Note the similarity to the IMO 2011 inequality, and surprisingly the same method works. P … more →
wrote 9 months ago: Consider a polynomial Albert Einstein and Homer Simpson are playing the following game. In turn, the … more →
wrote 10 months ago: Let be a rational number and let be a positive integer. Prove that the polynomial is irreducible in … more →
wrote 10 months ago: Let be a continuously differentiable function that satisfies for all . Prove that for all . 45.56443 … more →
wrote 10 months ago: Given an integer , let be the group of permutation of the numbers . Two players and play the followi … more →
wrote 10 months ago: Let be a fixed positive integer. Determine the smallest positive rank of an matrix that has zeros al … more →
wrote 10 months ago: For every positive integer denote denote the number of ways to express as a sum of positive integer. … more →
wrote 11 months ago: Problem 1 We are given a positive integer and a rectangular board with dimensions . The rectangle is … more →
wrote 11 months ago: I decided to test myself on solving some IMO problems. Here are my solutions for IMO 1995 Day 1. Apa … more →
wrote 1 year ago: Let be the set of positive integers. Find all functions such that the following conditions both hold … more →
wrote 1 year ago: Let be a positive integer. Let For each subset of , we write for the sum of all elements of , with t … more →
wrote 1 year ago: Prove that for all positive real numbers and . Balkan Mathematical Olympiad 2012 Problem 2 Solution: … more →
wrote 1 year ago: Let , and be points lying on a circle with centre . Assume that . Let be the point of intersection o … more →
wrote 1 year ago: A matrix with complex entries is called normal if , where is the conjugate transpose of . Prove that … more →
wrote 1 year ago: a) Compute . b) Let be an integer. Compute . a) Make the change of variable . The limit becomes Prov … more →
wrote 1 year ago: Prove that there is no continuous function such that and . Proof: As noted in the first comment, a c … more →