Cho A = 2/3^2 2/5^2 ... 2/2025^2 . Chứng minh A < .
Giải thích
A = 232+252+...+220252.
A = 23.3+25.5+...+22025.2025
A < 22.4+24.6+...+22024.2026
A < 12−14+14−16+....+12024−12026=12−12026=5062013
Vậy A < 5062013.
A = 232+252+...+220252.
A = 23.3+25.5+...+22025.2025
A < 22.4+24.6+...+22024.2026
A < 12−14+14−16+....+12024−12026=12−12026=5062013
Vậy A < 5062013.