经济数学基础形成性考核册及参考答案
作业(一)
(一)填空题 1.limx?0x?sinx?___________________.答案:0 x?x2?1,x?02.设f(x)??,在x?0处连续,则k?________.答案:1 ?k,x?0?3.曲线y?x在(1,1)的切线方程是 .答案:y?211x? 224.设函数f(x?1)?x?2x?5,则f?(x)?____________.答案:2x 5.设f(x)?xsinx,则f??()?__________.答案:?(二)单项选择题 1. 函数y?π2π 2x?1的连续区间是( )答案:D 2x?x?2A.(??,1)?(1,??) B.(??,?2)?(?2,??)
C.(??,?2)?(?2,1)?(1,??) D.(??,?2)?(?2,??)或(??,1)?(1,??) 2. 下列极限计算正确的是( )答案:B A.limxxx?0?1 B.lim?x?0xx?1
C.limxsinx?01sinx?1 D.lim?1
x??xx,则
( ).答案:B
C.
D.
3. 设A.
B.
4. 若函数f (x)在点x0处可导,则( )是错误的.答案:B
A.函数f (x)在点x0处有定义 B.limf(x)?A,但A?f(x0)
x?x0 C.函数f (x)在点x0处连续 D.函数f (x)在点x0处可微
5.当x?0时,下列变量是无穷小量的是( ). 答案:C A.2 B.(三)解答题 1.计算极限
xsinx C.ln(1?x) D.cosx xx2?3x?21x2?5x?61?? (2)lim2? (1)limx?1x?2x?6x?822x2?11?x?11x2?3x?51?? (4)lim2? (3)limx?0x??x23x?2x?43x2?4sin3x3?4 (5)lim? (6)limx?2x?0sin5xsin(x?2)51?xsin?b,x?0?x?2.设函数f(x)??a,x?0,
?sinxx?0?x?问:(1)当a,b为何值时,f(x)在x?0处有极限存在? (2)当a,b为何值时,f(x)在x?0处连续.
答案:(1)当b?1,a任意时,f(x)在x?0处有极限存在; (2)当a?b?1时,f(x)在x?0处连续。 3.计算下列函数的导数或微分: (1)y?x?2?log2x?2,求y? 答案:y??2x?2ln2?(2)y?x2x21 xln2ax?b,求y?
cx?dad?cb 2(cx?d)答案:y??(3)y?13x?5,求y?
答案:y???32(3x?5)3
(4)y?答案:y??x?xex,求y?
12xax?(x?1)ex
(5)y?esinbx,求dy
ax答案:dy?e(asinbx?bcosbx)dx
(6)y?e?xx,求dy
1x11x?2ex)dx 答案:dy?(2x(7)y?cosx?e?x,求dy 答案:dy?(2xe?x?n212sinx2x)dx
(8)y?sinx?sinnx,求y? 答案:y??n(sinn?1xcosx?cosnx)
(9)y?ln(x?1?x2),求y? 答案:y??11?xcot1x2
(10)y?2?1x1?3x2?2xx3,求y?
ln21?21?6?x?x 答案:y??126x2sinx4.下列各方程中y是x的隐函数,试求y?或dy (1)x?y?xy?3x?1,求dy 答案:dy?222cot5y?3?2xdx
2y?xxy(2)sin(x?y)?e?4x,求y?
4?yexy?cos(x?y)答案:y?? xyxe?cos(x?y)5.求下列函数的二阶导数: (1)y?ln(1?x),求y??
22?2x2答案:y??? 22(1?x)(2)y?1?xx,求y??及y??(1)
3?21?2??答案:y?x?x,y??(1)?1
4453作业(二)
(一)填空题 1.若2.
?f(x)dx?2x?2x?c,则f(x)?___________________.答案:2xln2?2
?(sinx)?dx?________.答案:sinx?c ?f(x)dx?F(x)?c,则?xf(1?x2)dx? .答案:?1F(1?x2)?c 23. 若
de4.设函数ln(1?x2)dx?___________.答案:0 ?dx15. 若P(x)??0x11?t2dt,则P?(x)?__________.答案:?11?x2
(二)单项选择题
2
1. 下列函数中,( )是xsinx的原函数. A.
11cosx2 B.2cosx2 C.-2cosx2 D.-cosx2 22答案:D
2. 下列等式成立的是( ).
A.sinxdx?d(cosx) B.lnxdx?d()
C.2dx?x1x1d(2x) ln2 D.
1xdx?dx
答案:C
3. 下列不定积分中,常用分部积分法计算的是( ). A.cos(2x?1)dx, B.x1?xdx C.xsin2xdx D.答案:C
4. 下列定积分计算正确的是( ). A.
C.
??2?x?1?x2dx
?1?12xdx?2 B.?2316?1dx?15
?????(x???x)dx?0 D.?sinxdx?0
答案:D
5. 下列无穷积分中收敛的是( ).
A.
???1??1????1xdx B.?dx C.?edx D.?sinxdx
101xx2答案:B
(三)解答题
1.计算下列不定积分
3x(1)?xdx
e3xxe?c 答案:3lne(2)
?(1?x)2xdx
3542答案:2x?x2?x2?c
35x2?4dx (3)?x?212x?2x?c 21(4)?dx
1?2x1答案:?ln1?2x?c
2答案:
(5)x2?xdx
?212答案:(2?x)2?c
3(6)
3?sinxxdx
答案:?2cosx?c
x?2dx
xx答案:?2xcos?4sin?c
22(7)xsin(8)ln(x?1)dx
答案:(x?1)ln(x?1)?x?c 2.计算下列定积分
?