Question

[Phạm Vân Nhi]

Cho S=1-1/2+1/3-1/4+...+1/2013-1/2014+1/2015

Và P=1/1008+1/1009+1/1010+...+1/2014+1/2015

Tính (S-P)^2016

Answer 1

[Vũ Quang Vinh]

Theo đầu bài ta có:
\(S=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2013}-\frac{1}{2014}+\frac{1}{2015}\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2013}+\frac{1}{2014}+\frac{1}{2015}\right)-2\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2014}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2013}+\frac{1}{2014}+\frac{1}{2015}\right)-\left(1+\frac{1}{2}+...+\frac{1}{1007}\right)\)
\(=\frac{1}{1008}+\frac{1}{1009}+...+\frac{1}{2015}\)
\(\Rightarrow S=P\)
Vậy ( S - P )²⁰¹⁶ = 0²⁰¹⁶ = 0

Answer 2

[Thảo Vy Đặng Thị]

sai roi