Contact us
Choose a category below so we can get back to you as quickly as possible.
1/n(n+1)=1/n-1/(n+1) 原式=1/1×2+1/2×3+1/3×4+1/4×5+1/5×6 =1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6 =1-1/6 =5/6
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.