∵f(x)=
1+x2
,x<0
e?x
,x≥0
∴当x∈[1,2)时,x-2<0,此时f(x-2)=1+(x-2)2;
当x∈[2,3]时,x-2≥0,此时f(x-2)=e-(x-2)
∴f(x?2)=
1+(x?2)2
,1≤x<2
e?(x?2)
2≤x≤3
∴
f(x?2)dx=
∫
f(x?2)dx+
∫
f(x?2)dx=
∫
[1+(x?2)2]dx+
∫
e?(x?2)dx
∫
=[x+
(x?2)31 3
+[?e?(x?2)
]
]
=
?e?17 3