so sánh: A=1/2^2 + 1/3^2 + 1/4^2 +...+ 1/98^2 + 1/99^2 và B=672/2019
1 câu trả lời
A=1/2^2 + 1/3^2 + 1/4^2 +...+ 1/98^2 + 1/99^2 =1/2.(1/2.1/3.144..............1/99)
=1/2.99=49,5
A=1/2^2 + 1/3^2 + 1/4^2 +...+ 1/98^2 + 1/99^2 =1/2.(1/2.1/3.144..............1/99)
=1/2.99=49,5