设 f(x)=1+ln x 2-x ,则 f( 1 2013 )+f( 2 2013 )+f( 3 2013 )+

设 f(x)=1+ln x 2-x ,则 f( 1 2013 )+f( 2 2013 )+f( 3 2013 )+…+f( 4025 2013 ) =______.
2025-06-24 18:33:15
推荐回答(1个)
回答1:

f(x)=1+ln
x
2-x

∴f(t)+f(2-t)=1+ln
t
2-t
+1+ln
2-t
t
=2+ln
t
2-t
?
2-t
t
=2
f(
1
2013
)+f(
4025
2013
)
=2, f(
2
2013
)+f(
4024
2013
)=…=f(
4025
2013
)+f(
1
2013
)
=2
∴S= f(
1
2013
)+f(
2
2013
)+f(
3
2013
)+…+f(
4025
2013
)

S=f(
4025
2013
)+ f(
4024
2013
)
…+f(
1
2013
)

2S=2×4025
∴S=4025
故答案为:4025