.
《经济数学基础12》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
x2?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??xx3. 设y?lg2x,则dy?( ).答案:B A.
11ln101dx B.dx C.dx D.dx 2xxln10xx4. 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.2x B.(三)解答题 1.计算极限
sinx C.ln(1?x) D.cosx xx2?3x?21x2?5x?61?? (2)lim2? (1)lim2x?1x?22x?1x?6x?821?x?11x2?3x?51?? (4)lim2? (3)limx?0x??3x?2x?4x23x2?4sin3x3?4 (5)lim? (6)limx?2sin(x?2)x?0sin5x51?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?
2x2答案:y??2x?2ln2?(2)y?x1 xln2ax?b,求y?
cx?dad?cb
(cx?d)2答案:y??(3)y?13x?5,求y?
答案:y???32(3x?5)3
--
.
(4)y?答案:y??(5)y?ex?xex,求y?
12xax?(x?1)ex
sinbx,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?1?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
222cot1x5答案:dy?y?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)
533?1?答案:y???x2?x2,y??(1)?1
44作业(二)
(一)填空题 1.若2.
?f(x)dx?2?x?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
1. 下列函数中,( )是xsinx2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()
1x--
.
C.2dx?x1d(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.
??2?x?2dx
答案:C
4. 下列定积分计算正确的是( A.
?1?12xdx?2 C.
????(x2?x3)dx?0 答案:D
5. 下列无穷积分中收敛的是( A.
???1xdx B.???111x2dx答案:B (三)解答题
1.计算下列不定积分
(1)?3xexdx
3x答案:ex?c ln3e(2)
?(1?x)2xdx
35答案:2x?423x2?5x2?c
(3)?x2?4x?2dx 1?x. B.?16?1dx?15
D.????sinxdx?0
). C.???0exdx D.???1sinxdx
--
)