问题
填空题
For real number a,let[a]denote the maximum integer which does not exceed a.For example,[3.1]=3,[-1.5]=-2,[0.7]=0 Now let f(x)=(x+1)/(x-1),then[f(2)]+[f(3)]+…+[f(100)]=______.(英汉小词典real number:实数;the maximum integer which does not exceed a:不超过a的最大整数)
答案
∵f(x)=
,x+1 x-1
∴f(2)=
=3,f(3)=2+1 2-1
=2,3+1 3-1
f(4)=
=4+1 4-1
,f(5)=5 3
=5+1 5-1
,…f(100)=3 2
=100+1 100-1
,101 99
∴[f(2)]=3,[f(3)]=2,[f(4)]=[f(5)]=…[f(100)]=1,
∴[f(2)]+[f(3)]+…+[f(100)],
=3+2+1+…+1,
=5+1×97,
=102.
故答案为:102.