?通解为
y?e??1x?P(x)dx?dxP(x)dx?xdxx?x?[?Q(x)edx?C]?e[?eedx?C]11 4?
代入yx?1[?e?xdx?C]?x1x[(x?1)e?C]y?1xx 6?
x?1,得C?1,?特解为
[(x?1)e?1] 8?
四、解答题
1、解:
????2xzdydz?yzdzdx?zdxdy?2???(2z?z?2z)dv????zdv?? 4?
?2?0???r?03cos?sin?drd?d? 6?
2?方法一: 原式=方法二: 原式=
?d??40cos?sin?d??2?rr2rdr?13?2 10?
2?2?0d??rdr?0n?11zdz?2??r(1?r)dr?0?2 10?
?2、解:(1)令
?un?(?1)n3n?1limun?1unn??n?13?lim?nn??3nn?1?13?1??n?1n3n?1收敛, 4?
??(?1)n?1n?1n3n?1绝对收敛。 6?
?n?s(x)?(2)令
?nxn?1x0?x?nxn?1?n?1n?1?xs1(x)x1?x 2?
x1?x)??1(1?x) 5?
2?x0?s1(x)dx???n?1nxdx??n?1x?n?s1(x)?(?s(x)?x(1?x)2x?(?1,1)高等数学(下)模拟试卷二参考答案
一、填空题:(每空3分,共15分)
1、 {(x,y)|y?4x,0?x?y?1} 2、edx?2edy 3、?022222 6?
1dy?eeyf(x,y)dx
14、12(55?1) 5、y?(C1?C2x)e
x二、选择题:(每空3分,共15分) 1. A 2.B3. B 4.D5. A
三、计算题(每题8分,共48分)
??1、解: A(0,2,4)????n1?{1,0,2}??n2?{0,1,?3} 2?
ij01x?k???s?n1?n2?102??2i?3j?k?3y?23?z?41 6? 8?
?直线方程为?22、解: 令u?sinxcosy?z?v?ex?y 2?
?z?u?z?vx?y????f1??cosxcosy?f2??e ?x?u?x?v?x 6?
?z?z?u?z?vx?y?????f1??(?sinxsiny)?f2??e?y?u?y?v?y 8?
3、解:
?D:0????40?r?1, 3?
?40??arctanDyxdxdy???r?drd???D?d??rdr?01?264 8?
??fx(x,y)?2x?6?0??fy(x,y)?10y?10?0 得驻点(3,?1) 4? 4.解: ?A?fxx(x,y)?2,B?fxy(x,y)?0,2C?fyy(x,y)?10 6?
?A?2?0,xAC?B?20?0?极小值为f(3,?1)??8 8?
x5.解:P?esiny?2y,?PQ?ecosy?2,
?Q?x?ecosy,2?
x有?y?ecosy?2,OA:x 取A(2a,0),
y?0,x从0?2a 4?
?LPdx?Qdy?2?OAPdx?Qdy???(D?Q?x??P?y)dxdy???2dxdy??aD2 6?
?原式=?a-6.解:
P??1x?1?OAPdx?Qdy322=?a?0??a 8?
,Q?(x?1)2 2? dx?C]?e?x?1dx213?通解为
y?e??P(x)dx[?Q(x)e?1P(x)dx[?(x?1)2e3??x?1dx1dx?C] 4?
?(x?1)[?(x?1)2dx?C]?(x?1)[(x?1)2?C]3 8?
四、解答题
1、解:(1)令
?un?(?1)n?12sinn?3nlimun?1un2?limn??n?1sin?33n?1n??2sinn?n?23?14?
??2sinn?1n?3收敛,
?n???(?1)n?1n?12sinn?3绝对收敛 6?
ns(x)?(2)令
??n?1xnn? xn?1??xn?s?(x)?????n?1?n??n?1?11?x, 2?
?s(x)??x0s?(x)dx?s(0)??ln(1?x) 4?
2、解:构造曲面?1:z?1,上侧
??2xdydz?ydzdx?zdxdy???2xdydz?ydzdx?zdxdy??1 2?
????(2?1?1)dv?4???dv?4???2?0d??rdr?011r2dz?8??10(1?r)rdr?2?2
4? 6? 8? ?I?2????2xdydz?ydzdx?zdxdy? 10?
1?2????dxdy??Dxy高等数学(下)模拟试卷三参考答案
一.填空题:(每空3分,共15分)
?2??2?0,?0,??3?X?1且x?0?或?3? 1.;2.a;3. 2dx;4.0;5. ?二.选择题:(每空3分,共15分) 1.A;2.D;3.A;4.A;5.C.
1 12?
三.计算题:
1.
?lim?1?kx??kxx?01?(?k)??1?kx?k4??e?k2?
22?2 2.
??limx?01cosxsintdtx1x322??lim?(?sincosx)(?sinx)3x4?1xx?0??2?2?
dydx?elnsin 3.
四.计算题:
y1?1?cos??2?1x?x?sinx1??1x2elnsincot1x
1?ey??y?xy??0;x?0,y?02?;dydxx?0?ye?xyx?0?013? 1.
?xarcsinx?;
1?x22.原式
3?x11?x22dx2??xarcsinx??2??2d(1?x)22?
3?xarcsinx?1?x?c?2?
3 3. 原式
??0?0?2?(sinx)2cosxdxd(3a?x)?23a?x2222??20(sinx)2dsinx?3a?(sinx)2dsinx3??451?
4.原式五.解答题: 1
?3a3?22???3a?x???02??3a?3a?3a21?。
.
y??2t1?t22?,t?2,k??431?,x?6a5,y?12a51?,切线:4x?3y?12a?0,法线:3x-4y+6a=01?1? 2.
设f(x)?lnx,x?b,a?,a?b?0,lna?lnb?2032?2?1?(a?b),b???a,2?1a?lna?lnba?b?1b2?S?3.(1)
?xdx?x4?????4?022??42?
82?Vy? (2)、
?8025????3?2??4?y3?dy???4y?y3?5????0?645?2?
高等数学(下)模拟试卷四参考答案
一.填空题:(每空3分,共15分)
12641?21x1.2?x?4;2.3;3. dx;4. 3;5. 2?5y。
二.选择题:(每空3分,共15分)
1. C;2. D;3. B;4. B;5. C。
??1??lim?x???1??3?2x??1?2x?x3?2x3?32三.1.
??1????1??3??3?1?5??2x?2x??lim?23??e??2x?(?2)x??11????1??2x?2x??
2.
?limdy?1?cosx3x1cosex2sin2?2x22?x?02?limxx?03xx2?16x2?
3? 3.dx 四.
?(?sine)?e3???ecotex
1.
2. 3.
y????1t2?1,dydx222??tt22?t?32?;
2??x2dsinx?xsinx??sinx?2xdx10?xsinx?2xcosx?2sinx?c2102?24?
?xarctanx??x?0111?x2dx2???4?ln(1?x)22???4??2?ln22?2?
?21??x?2sint,?1? 4.
?202cost?2costdtsin2t?2???t?2???0。
五.解答题
y??12x?12x,y???36x?24x,x1?0,x2?0?、???,??223为拐点,2?3222? 1.
2.
??2,???为凹区间,?0,?3??3?4?? 为?
凸区间
?1,x?1??xf(x?1)??,(2?)?1?,x?1x??1?e?1011?exdx??21x1dx(2?)?lnex10?ln(1?e)x10?lnx21(2?)
331? ?1?ln(1?e)?2ln2(2)
? 3.(1)、
??01x?x2?dx4??2x???x2??33??024?2??12312??
?310Vx? (2)、
?10??x?x?dx4?xx??????5?0?25?2?
高等数学(下)模拟试卷五参考答案
一、填空题:(每空3分,共21分)
1、?(x,y)x?y,y?0?, 2、2xex?y22dx?2yex?y22dy,3、0,4、2?,
5、?01dy?eeyf(x,y)dx,6、条件收敛,7、y??cosx?c(c为?常数),
z二、选择题:(每空3分,共15分)1、A,2、D,3、A,4、D,5、B
三、解:1、令F(x,y,z)?lnz?e?xy???1?
F?zyz??x?z?xFz1?ze ???4?
?z
???7?
2、所求直线方程的方向向量可取为?1,?2,3????2?
x?1?y??FyFz?xz1?zez则直线方程为:1??y?2?z?23???7?
3、原式
??40d??rdr023???4?
四、解:1、令
?? ???7?