问题
解答题
设f(x)=
(1)求f(x)表达式; (2)计算f(x)+f(1-x); (3)试求f(
|
答案
(1)∵f(x)=
过点( 4x 4x+a
,1 2
)1 2
∴f(
)=1 2
=4 1 2 4
+a1 2
=2 2+a
,解得a=2∴f(x)=1 2 4x 4x+2
(2)f(x)+f(1-x)=
+4x 4x+2
=41-x 41-x+2
=4x(41-x+2)+41-x(4x+2) (4x+2)(41-x+2)
=18+2•4x+2•41-x 8+2•4x+2•41-x
(3)∵f(x)+f(1-x)=1
∴f(
)+f(1 2007
)=f(2006 2007
)+f(2 2007
)=…=f(2005 2007
)+f(1002 2007
)=f(1005 2007
)+f(1003 2007
)=11004 2007
f(
)+f(1 2007
)+f(2 2007
)++f(3 2007
)+f(2005 2007
)=10032006 2007