Art of Problem Solving
AoPS Online
Math texts, online classes, and more
for students in grades 5-12.
Visit AoPS Online ‚
Books for Grades 5-12 Online Courses
Beast Academy
Engaging math books and online learning
for students ages 6-13.
Visit Beast Academy ‚
Books for Ages 6-13 Beast Academy Online
AoPS Academy
Small live classes for advanced math
and language arts learners in grades 2-12.
Visit AoPS Academy ‚
Find a Physical Campus Visit the Virtual Campus

Revision history of "1990 APMO Problems/Problem 2"

Diff selection: Mark the radio boxes of the revisions to compare and hit enter or the button at the bottom.
Legend: (cur) = difference with latest revision, (prev) = difference with preceding revision, m = minor edit.

  • (cur | prev) 06:59, 26 November 2024‎ Fkcosx (talk | contribs)‎ . . (1,041 bytes) (+1,041)‎ . . (Created page with "We have to prove <cmath>S_k S_{n-k} \geq {n \choose k}^2 a_1 a_2 \cdots a_n.</cmath> Let, \begin{align*} S_k & = \sum_{i=1}^{n\choose k}t_i \\ S_{n-k} & = \left(\prod_{m=1}...")
Retrieved from "https://artofproblemsolving.com/wiki/index.php/1990_APMO_Problems/Problem_2"