若f(x)是奇函数,g(x)是偶函数,且f(x)+g(x)=1/x−1,则f(x)=_.

问题描述:

若f(x)是奇函数,g(x)是偶函数,且f(x)+g(x)=

1
x−1
,则f(x)=______.

∵f(x)+g(x)=

1
x−1
,①
f(−x)+g(−x)=
1
−x−1

∵f(x)是奇函数,g(x)是偶函数,
−f(x)+g(x)=
1
−x−1
,②
①+②,得2g(x)=
1
x−1
+
1
−x−1
=
2
x2−1

g(x)=
1
x2−1

f(x)=
1
x−1
1
x2−1
=
x
x2−1

故答案为:
x
x2−1