设f(x)=1+x2 x<0e?x x≥0,求∫31f(x?2)dx

设f(x)=1+x2 x<0e?x x≥0,求∫31f(x?2)dx.
2025-06-21 09:14:45
推荐回答(1个)
回答1:

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+
1
3
(x?2)3
]
+[?e?(x?2)
]

=
7
3
?e?1