第四章
习题A(作业题)(作业题)
1.(1)原式
不定积分
13∫32x3dx432x3c2
1
2
(2)原式si
xcosx(3)原式2arcsi
∫
32
dx∫cosxdcosx
32
2cosx
c
∫
xdx2xarcsi
x2∫xdarcsi
xx1dx2xarcsi
x21xc
2xarcsi
x2∫
2.y
1x2x
∫xdxl
xc
1
ye23,得c1,故yl
x1
习题B(练习题)(练习题)
1.填空题(1)yc(2)
2cosx
c
(3)e(4)
x
c
l
si
xcosxdxsi
x12(5)xc2
2
(6)2xcosx(7)f2x(8)
11x22c3
3
(9)arcsi
xπ
cosxcsi
2x13127(11)xx,原题改为fxdxx2xdx326
(10)
f(12)2l
xl
xc
2
(13)l
1xx2c2.选择题(1)A(2)C(3)B(4)B(5)A(6)B(7)B(8)B
9、D10、B11、C3、计算下列不定积分1∫secxsecxta
xdx∫sec2xsecxta
xdxta
xsecxc2
∫ta
3
10
xsec2xdx∫ta
10xdta
x
1ta
11xc11
∫xl
xl
l
xdx∫l
xl
l
x
4
1
1
1
dx11dl
x1∫dl
x∫∫dl
l
xl
l
l
xcxl
xl
l
xl
l
xl
xl
l
x
si
x1ta
xcosxsi
x1cosx∫1ta
xdx∫si
xdx∫cosxsi
xdx∫cosxsi
xdsi
xcosxl
cosxsi
xc1cosx
5∫
si
tt
dt2∫si
tdt2costc
(6)
11exexex1dx∫dx∫1dxx∫dex1xl
1excxxx∫1ex1e1e1e
(7)
∫
l
ta
x2dxl
ta
xdl
ta
x1l
ta
x2c∫si
x2222
(8)
f∫xta
xsec
11222∫xdta
x2xta
x∫ta
xdx2xta
2x1xta
2x1ta
x∫sec2x1dxxc22222
2
xdx∫xta
xdta
x
(9)
∫
1x1x
dx∫
1dx2arcsi
2xc211x242
1
(10)
∫xl
x
(11)
1l
x
2
dx∫d
11cxl
xxl
x
∫
arcsi
x1x
设
dx
则
arcsi
xt
xsi
2t
得到原式为:
∫cost2si
tcostdt2∫tsi
tdt2∫tdcost2tcost∫costdt2tcost2si
tc
21xarcsi
x2xc
t
(12)
∫x
2
2x31dx∫2dx23x10l
x23x10c3x10x3x10
(13)
1111111ex1dx∫2xdex∫xxdex(l
ex1l
ex1)cl
xc∫exex2e1e122e1e1
(14)
33
∫xl
x21l
xdx∫xl
x2dxl
x
2xl
x2c5
5
f(15)∫原式∫
112x
dx设2xt
t1dttl
tr