解:
1/(1+√2)+1/(√2+√3)+1/(√3+2)+1/(2+√5)+1/(√5+√6)
=(√2-1)/(2-1)+(√3-√2)/(3-2)+(2-√3)/(4-3)+(√5-2)/(5-4)+(√6-√5)/(6-5)
=(√2-1)+(√3-√2)+(2-√3)+(√5-2)+(√6-√5)
=√2-1+√3-√2+2-√3+√5-2+√6-√5
=√6-1
1/(1+√2)+1/(√2+√3)+1/(√3+2)+1/(2+√5)+1/(√5+√6)
= ( √2-1 ) / 1 + (√3-√2 ) /1 + (2- √3)/1 + (√5-2)/1 + (√6-√5)/1
= √2-1 +√3-√2 +2- √3+ √5-2 + √6-√5
= -1 +√6
= √6-1
原式=根号2-1+根号3-根号2+2-根号3+根号5-2+根号6-根号5=根号6-1
原式=√6-1
1/(1+√2)=√2-1 之后的以此类推