问题 填空题
g(x)=1-2x,f(g(x))=
1-x2
x2
(x≠0)
,则f(
1
2
)
=______.
答案

令1-2x=

1
2
解得x=
1
4

∴f(

1
2
)=f(1-2×
1
4
)=f(g(
1
4
))=
1-(
1
4
)
2
(
1
4
)
2
=
15
16
1
16
=15.

故答案为:15.

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