2017专升本 高等数学(二)(工程管理专业)
一、选择题(1~10小题,每小题4分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的)
x2?1?() 1. limx?1x?1
x?1??x?1??x2?1?lim?lim?x?1??2. C limx?1x?1x?1x?1x?12. 设函数f?x?在x?1处可导,且f??1??2,则limx?0f?1?x??f?1??()
x
1B.? 2C.
f?1?x??f?1?f?1?x??f?1???lim??f??1???2. A limx?0x?0x?x?π?3. 设函数f?x??cosx,则f???=()
?2?1 2
1 2
π???A 因为f?x??cosx,f??x???sinx,所以f?????sin??1.
2?2?4. 设函数f?x?在区间?a,b?连续且不恒为零,则下列各式中不恒为常数的是() A.f?a?
B.
?f?x?dx
abf?x? C.lim?x?bxD.
?f?t?dta
?D 设f?x?在?a,b?上的原函数为F?x?.A项,??f?a????0;B项,
?bf?x?dx????F?b??F?a????0;C项,?limf?x?????F?b????0;D项,
???????x?b?????a???xf?t?dt???f?x?.故A、B、C项恒为常数,D项不恒为常数.
????a?xdx?5. ?()
3A. 3x?C 3B. x?C
2x3?CC. 3
x?C2D.
x32?Cxdx?3C ?.
6. 设函数f?x?在区间?a,b?连续,且I?u???f?x?dx??f?t?dt,a?u?b,则
aauuI?u?()
A.恒大于零
B.恒小于零 C.恒等于零 D.可正,可负
C 因定积分与积分变量所用字母无关,故
I?u???f?x?dx??f?t?dt??f?x?dx??f?x?dx??f?x?dx?0.
aaauauuuaa7. 设函数z?ln?x?y?,则
?z?x?1,1??().
B.
1 2B 因为z?ln?x?y?,
?z?z1?,所以?xx?y?x?z=(). ?y?1,1?1?. 28. 设函数z?x3?y3,则A. 3x2 B. 3x2?3y2
y4C.
4D. 3y2
D 因为z?x3?y3,所以
???2z
?z=3y2. ?y9. 设函数z=x??,则?x?y=(). A. ?? B.?? C.x?? D.y??
B 因为z=x??,则?x=e, ?x?y=??.
y
???????????z
?2z
??10. 设事件A,B相互独立,A,B发生的概率分别为,,则A,B都不发生的概率为().
事件A,B相互独立,则A,B也相互独立,故P(AB)=P(A)P(B)=×=. 二、填空题(11~20小题,每小题4分,共40分) 11.函数f?x??5的间断点为x=________. x?11 f?x?在x=1处无定义,故f?x?在x=1处不连续,则x=1是函数f?x?的间断点.
12.设函数f(x)={
lnx,??≥1,
在x?1处连续,则a=________.
a?x,??<11 limf?x??lim?a?x??a?1,因为函数f?x?在x?1处连续,故??x?1x?1x?1?limf?x??f?1??ln1?0,即a-1=0,故a=1.
13.limsin2x=________.
x?03x2sin2x2cos2x2?lim? lim
x?0x?0 33x33.
14. 当x→0时,f?x?与sin2x是等价无穷小量,则limf?x??1
x?0sin2x.
f?x?=________.
x?0sin2x1 由等价无穷小量定义知,lim15. 设函数y?sinx,则y???=________.
?cosx
因为y?sinx,故y??cosx,y????sinx,y?????cosx.
16.设曲线y=ax2+2x在点(1,a+2)处的切线与直线y=4x平行,则a=________. 1 因为该切线与直线y=4x平行,故切线的斜率k=4,而曲线斜率y′(1)=2a+2,故2a+2=4,即a=1. 17. ?2xedx?________.
e?C ?2xedx??edx2?ex?C.
x2x2x2x2218.
?π20esinxcosxdx? ________.
π20sinxe-1 ?e19.
cosxdx??eπ20sinxd?sinx??eπsinx20? =e-1.
???01dx?________. 21?x??aaπ11π dx?limdx?limarctanx?limarctana?22??00a??a??a?? .201?x1?x220. 设函数z?ex?y,则dz=________.
exdx?dy dz?
?z?zdx?dy?exdx?dy. ?x?y三、解答题(21~28题,共70分.解答应写出推理、演算步骤)
21.(本题满分8分) 计算lim?1?x?.
x?02x1??lim?1?x?=lim??1+x?x??e2x?0??. 解: x?02x222.(本题满分8分)
设函数y=sinx2+2x,求dy.
解:因为y???x2??cosx2?2?2xcosx2?2, 故dy?2xcosx2?2dx. 23.(本题满分8分) 计算?lnxdx.1e??
eee解:?lnxdx?xlnx??xd?lnx?1 1124.(本题满分8分)
设y?y?x?是由方程ey?xy?1所确定的隐函数,求解:方程ey?xy?1两边对x求导,得
dy. dxeydydy?y?x?0. dxdxdyy??y. dxe?x于是
25.(本题满分8分)
已知离散型随机变量X的概率分布为 0 1 (1)求常数a; (2)求X的数学期望E(X)和方差D(X). 解: (1)因为+++a=1,所以a=. (2) E(X)=0×+1×+2×+3×
2 3