Comentarii Jbmo 2015 – Premium & Pro

A problem involving an acute triangle and perpendicular lines from a midpoint. The goal was to prove an equality between two angles,

for positive real numbers. The minimum value was found to be 3.

. Commentary suggests this was a very accessible problem, possibly even at a 5th or 6th-grade level, which resulted in a high number of maximum scores. Comentarii JBMO 2015

. Notes indicate that many participants were able to solve this using analytical or vector methods.

Problem 3 (Geometry) was noted for its "attackability" through multiple different methods, including classic Euclidean geometry, vectors, and coordinate geometry. A problem involving an acute triangle and perpendicular

A game-theory problem on a board involving L-shapes. It required determining the minimum number of marked squares needed to ensure a certain outcome. Key Commentary Insights

The competition consisted of four problems covering algebra, number theory, geometry, and combinatorics. Notes indicate that many participants were able to

This problem involved minimizing a specific expression given the constraint