设f(x)=4x4x+2,则f(1/11)+f(2/11)+f(3/11)+…+f(10/11)=_.

问题描述:

f(x)=

4x
4x+2
,则f(
1
11
)+f(
2
11
)+f(
3
11
)+…+f(
10
11
)=______.

令α+β=1,则α=1-β
f(α)+f(β)=

4α
4α+2
+
4β
4β+2
=
41−β
41−β+2
+
4β
4β+2
=
4
4+2×4β
+
4β
2×4β+4
=1
即两自变量的和为1时,函数值的和也是1
f(
1
11
)+f(
2
11
)+f(
3
11
)+…+f(
10
11
)
=5
故答案为5