来自戴洪德的问题
1/(1+√2)+1/(√2+√3)+1/(√3+2)+.+1/(3+√10)=
1/(1+√2)+1/(√2+√3)+1/(√3+2)+.+1/(3+√10)=


1/(1+√2)+1/(√2+√3)+1/(√3+2)+.+1/(3+√10)=
1/(1+√2)+1/(√2+√3)+1/(√3+2)+.+1/(3+√10)=
分母有理化,=(√2-1)+(√3-√2)+(√4-√3)+...+(√10-√9)=√10-1.