微积分习题答案.docx
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微积分习题答案
习题答案
习题1-1
1.
(1)[-3,3];(2) (-
∞,0)∪(2,
+∞);
(3) (-2,1);(4) (-1.01,-1)∪(-1,0.99)
2.(1) [-1,0)∪(0,1);(2) (1,2];
(3) [-6,1).
3. (1) (-∞,1)∪(1,2],f(0)=0,f(2)=1.当a<0时,f(a)=1a,当0≤a≤1时,f(a)=2a,当1<a≤2
时,f(a)=1.
(2)(-2,2),f(0)=1,f((-a)2,当1<a<2时,f(a)=a2-1.
4.1.
5. (1)偶函数;
(2)非奇非偶函数;(3)奇函数
.
8.
(1)y=13arcsinx2;
(2)y=lo
g2x1-x
(3)f-1(x)=12(x+1), -1
≤x≤1,
2-2-x,1<x≤2.
9. (1) y=101+x2(-∞,+∞);(2) y=
sinxln2,(-∞,+∞);
(3) y=arctana2+x2(-∞,+∞).
习题1-2
1.
(1)y=3u,u=arcsinv,v=ax;(2) y=u
3,u=sinv,v=lnx;
(3) y=au,u=tanv,v=x2;(4) y=lnu,u=v2,v=lnw,w=t3
t=lnx.
2. (1) [-1,1],(2) [2kπ,(2k+1)π
],k∈Z;
(3)[-a,1-a];(4) (-∞,-1].
3.
(1)φ(x)=6+x-x2;
(2) g(x)=(1+x)2+(1+x)+1;
(3) f(x)=x2-2.
习题1-3
1.R(x)=4x-12x2.
2. R(x)≈130x,
117x+9100, 0≤x≤700,
700<x≤1000.
3. L=L(Q)=-15Q2+8Q-50,
=-Q5+8-50Q
.
习题2-1
略.
习题2-2
2. f(x)=-1,
1, x≤0
x>0,则limx→0f(x)
=1,但limx→0-f(x)=-1,limx
→0+f(x)=1,故limx→0f(x)不存在.
3. limx→0(x2+a)=a,limx
→0-e1x
=0,a=0.
习题2-3
2. ,,,,,,,.
3.
(1)无穷大量.
(2)x→0+时为无穷大量,x→1时为无穷小量.x→+∞时为无穷大量.
(3) x→0+时为无穷大量,x→0-时为无穷小量.
(4)无穷小量.
(5)无穷小量.
(6)无穷小量.
习题2-4
5. (1)3/5;(2) 0;(3) ∞;(4)1/3;
(5)4/3
6. (1)16;
(2)∞;(3) 3;
(4) -22;
(5) 3x2.(6) 43;(7) n(n+1)2;(8) 1;
(9) 1;(10) -1;(11) 0.
习题2-5
1.53;2. 25;
3. 1;4. 22;
5. 212;6. e-1;
7. e3;8. lna;
9. 2lna; 10. 0;11. e-12;12. 1;
13. 1;14. 1;15. e1
e;16. e-1.
习题2-6
3.tanx-sinx=O(x3)
4.
(1)ab;
(2)k22;(3)2;(4)24;
(5)1;(6)1;(7)49;(8)3.
习题2-7
4.
(1)x=1(可去),定义f
(1)=2;x=2(第二类);
(2)x=0(可去),定义f(0)=1;x=kπ,k≠0,为整数(第二类);
(3)x=0(第一类;
(4)x=2(第二类);x=-2(可去),定义f(-2)=0;
(5)x=0(可去),定义f(0)=0.
6. f(x)=sgnx,x=0(第一类),f(x)∈C[(-∞,0)∪(0,+∞)]
7. (1) 12;(2) 3;(3) 0;(4) π3;
(5)1.
习题3-1
1. 29.
2. -1x20.
3. 4x-y-4=0,8x-y-16=0
4. (1) -f′(x0);
(2)-f′(x0);(3)2f′(x0)
5. (1) 12x;(2)
-23x-53;
(3) 16x-56.
6. 连续但不可导.
8. (1) f′
(2)f′12,f′
9. f′(x)=cosx,
1, x<0,
x≥0.
10. a=2,b=-1.
11. (1)在x=0处连续,不可导;
(2)在x=0处连续且可导;
(3)在x=1必连续,不可导.
13.
(1)-0.78m/s;
(2)10-gt;(3)10g(s).
14.dQdtt=t0.
15. (1) limΔT→0Q(T+ΔT)
-Q(T)ΔT;(2) a+2bT.
习题3-2
1.
(1)3t;
(2)xx+12xlnx;
(3)2xsin2x-2xsinx+cosx-x2cosx-sin2x+x2sin
2x.
(4) 1-sinx-cosx(1-cosx)2;(5) sec
2x;
(6) xsecxtanx-secxx2-3secx·tanx
;(7) 1x1-2ln
10+3ln2;
(8) -1+2x(1+x+x2)2.
2. (1) 241+π2;(2) f′(0)=
325,f′(2)=1715;
(3) f′(1)=5.
3. 略.
4.
(1)3e3x;
(2)2x1+x4;
(3)12x+1e2x+1;
(4)2xln(x+1+x2)+1+x2;
(5) 2x·sin1x2-2x
cos1x2;(6) -3ax2sin2ax3;
(7) xx2·x2-1;(8) 2arcsinx24-x2;
(9) lnxx·1+ln2x;(10) nsinn-1x·cos(n+1)x;
(11) 11-x2+1-x2;(12
) -1(1+x)2x(1-x);
(13) -thx;(14) a2-x2.
5. 13.
6. 2x+3y-3=0;3x-2y+2=0;x=-1;y=0.
7.
(1)2xf′(x2);
(2)sin2x[f′(sin2x)-f′(cos
2x)].
8. (1) -x2-ayy2-ax;
(2)1-yx(lnx+lny+1);
(3)-ey+yexxey+ex;(4)
x+yx-y;
(5) ex+y-yx-ex+y.
9. (1) x+2(3-x)4(x+1)512(x+2)-43-x-5x+1;
(2)sinxcosxcos2xsinx-sinxlnsinx;
(3) e2x(x+3)(x+5)(x-4)2+1x+1-12(x+5)-12(x-4).
10. (1) sinat+cosbtcosat-sinbt;
(2) cosθ-θsinθ1-sinθ-θcosθ.
11. 3-2.
习题3-3
1.f(n)(x)=(-1)n-1(n-1)!
(1+x)n.
2.y(n)=(-1)n·an·n!
·(ax+b)-(n+1).
f(n)(x)=(-1)n2·n!
·1(x
-1)n+1-1(x+1)n+1
3.
(1) 0;
(2) 4e,8e;(3) 7200,720.
4.
(1)-b4a2y3;
(2) e
2y(3-y)(2-y)3;
(3)-2csc2(x+y)cot3(x+y);(4) 2x2y[3(y2+1)
2+2x4(1-y2)](y2+1)3.
5.
(1)-1a(1-cost)2;
(2)1f″(t).
6.
(1)4x2f″(x2)+2f′(x2);
(2)f″(x
)f(x)-[f′(x)]2f.
习题3-4
1.
(1)sint;
(2) -1ωcosωt;
(3) ln(1+x);(4)-12e-2x;
(5) 2x;(6) 13tanx;(7)ln2x2;(8) -1-x2.
2. (1) 0.21,0.2,0.01;(2) 0.0201,0
.02,0.0001.
3. (1) (x+1)exdx;
(2) 1-lnx〖
〗x2dx;
(3) -12xsinxdx;(4) 2ln5·5ln tanx·1sin2xdx;
(5) -12cscx2dx;(6) 8[xx(1+lnx)-12e2x]dx;
(7)121-x2arcsinx
+2arctanx1+x2d
x.
4.
(1)ey1-xeydx;
(2)
-b2xa2ydx;
(3)22-cosyds;(4)
1-y21+2y·1-y2dx.
5.
(1) 2.0083;(2) -0.01;(3) 0.7954.
习题3-5
1. (1) 1.1;(2) 650;(3) 650-50
129.
2. (1) 96.56;(2) 是,提高2.
3. (1) a,axax+b,aax+b;
(2) abebx,bx,b;
(3)axa-1,a,ax.
4.提高8%;提高16%.
5. 5.9.
习题4-1
1. ξ=π2.
2. (1) 满足,有ξ=0;(2) 不满足第二个条件,没有;
(3)不满足第一和第三个条件,有ξ=π2.
3. 有分别位于区间(1,2),(2,3),(3,4)内的三个根.
4. ξ=33.
习题4-2
1. (1) -35;(2)
12;(3) mnam-n;(
4) 1a
(5) 0;(6)0;(7) 1;(8)32;
(9)e;(10) e-2π
;(11) 1e;(12) ∞
(13) 13;(14) e-12.
2. m=-4,n=3
4. f″(x);
习题4-3
1.xex=x+x2+x32!
+…+xn(n-1)!
+1(n+1)!
(n+1+θx)eθxxn+1(
0<θ<1).
2. 1x=-1-(x+1)-(x+1)2-…-(x+1)n+(-1)n+1(x+1)n+1[-1+θ(x+1)]n+2(0<θ<1).
3. f(x)=-56+21(x-4)+37(x-4)2+11(x-4)3+(x-4)4.
4.
(1)16(提示:
只要将sinx展开成三次多
项式即可).
(2)12(提示:
令u=1x,再将ln(1+u
)展开成二次多项式).
习题4-4
1. (1) (-∞,-1)和(3,+∞)为增区间,(-1,3)为减区间,f(-1)=
3为极大值,f(3)=-61为极小值.
(2)(1,+∞)为增区间,(0,1)为减区间,f
(1)=1为极小值.
(3) (-∞,2)为增区间,(2,+∞)为减区间,f
(2)=1为极大值.
(4) (-∞,0)和(0,2)为增区间,(2,+∞)为减区间,f
(2)=-4为极大值.
5.当a=2时,f(x)在x=π3取极大值3.
习题4-5
1.15元
2. x=αcPQ11-α
3. (1) Q=3;(2) MC==6
4.
(1)1000件;
(2)6000件
5.
(1)431.325吨
(2)12次(3)30.452天(4)1366
43.9元
6. α=23(3-6)π.
7. t=14r2.
8. v=320000≈27.14(km/h)
习题4-6
1. (1) 在-∞,13下凸,13,+∞上凸,拐点1
3,227;
(2)在(-∞,-1)上凸,(-1,1)下凸,(1,+∞)上凸,拐点(-1,ln2)及(1,ln
2);
(3) 在(-∞,-2)上凸,(-2,+∞)下凸,拐点(-2,-2e-2);
(4) 在(-∞,+∞)下凸,无拐点;
(5)在(-∞,-3)上凸,(-3,6)上凸,(6,+∞)下凸,拐点6,227;
(6)在-∞,12上凸,12,+∞下凸,拐点12,earct
an12.
3. a=-32,b=92.
4. (1) 垂直渐近线x=0;
(2)水平渐近线y=0;
(3)水平渐近线y=0,垂直渐近线x=3;
(4)垂直渐近线x=12,斜渐近线y=12x+1〖
〗4.
5. (1) 定义域(-∞,+∞),极大值f
(1)=12
,极小值f(-1)=-12,拐点3,34,-3,-34,渐近线y=0;
(2)定义域(-∞,+∞),极大值f(-1)=π2-1,极小值f(1
)=1-π2,拐点(0,0),渐近线y=x+π,y=x-π;
(3)定义域(0,+∞),极大值f
(1)=2e,拐点,2,4e2,渐近线y=0.
习题5-1
1. (1) 27x7〖
〗2-103x32
+C;
(2)2x-43x
32+25x52+C;
(3)3xex1+ln3+C;(4) x+sinx2+C;
(5) 2x-523
xln2-ln3+C;(6) -(cotx+tanx
)+C.
2. (1) y=x2-2x+1;
(2)cosx+C;
(3) x-sinx;(4) Q=100013P
习题5-2
1.
(1)1a;
(2)17;(3)
110;(4)-12;
(5)112;(6)12;(7)-2;(
8)15;
(9)-1;(10)-1;(11)13;(12)1
2;
(13)-1;(14)32.
2. (1) 15e5t+C;(2) -18(3-2x)4+C;
(3) -12ln1-2
x+C;(4)
-12(2-3x)23+C;
(5) -2cost+C;(6) ln
lnlnx+C;
(7) 111tan11x+C;(8)
-12e-x2+C;
(9) lntanx+C;(10)
-lncos1+x2+C;
(11) arctanex+C;(12) -13
(2-3x2)12+C;
(13) -34ln1-
x4+C;(1
4) 12cos2x+C;
(15) 12arcsin2x3+
149-4x2+C;(1
6) x22-92ln(x2
+9)+C;
(17) 122ln2x-12x+1+C;(18)13lnx-2x+1+C;
(19)t2+14ωsin2(ωt+φ)+C;(20) -13ωcos3(ωt+φ)+C;
(21) 12cosx-110
cos5x+C;(22) 13sin
3x2+sinx2+C;
(23) 14sin2x-124
sin12x+C;(24) 13sec3x-
secx+C;
(25) (arctanx)2+C;(26) -1arcsinx+C;
(27) 12(lntanx)2+C;(28)
-1xlnx+C;
(29) a22(arcsinxa
-xa2a2-x2)+C;(30) x1+x2+C;
(31) x9-9-3arccos3
x+C;(32) 12(arcsinx+ln
x+1-x2)+C;
(33) arcsinx-x1+1-x2+C;(34) arcsinxa-a
2-x2+C;
(35) -4-x2x-arcsinx2+C;
(36) ln1+x+x2+2x-2xx
2+2x+C;
(37) -11+tanx+C;(38) x+
lnx1+xex+C.
习题5-3
1. (1) -xcosx+sinx+C;
(2)-(x+1)e-x
+C;
(3)xarcsinx+1-x2+C;(4)sin
x-cosx2e-x+C;
(5) -217e-2xx
2+4sinx2+C;(6)-12x2+xtanx+lncos
x+C;
(7)-t2+14
e-2t+C;
(8) x(arcsinx)2+21-x2
arcsinx-2x+C;
(9)12-15sin2x-110cos2x)ex+C;
(10)3e3x(3x2-23x+2+C;
(11) x2(coslnx+sinlnx)+C;
(12)-12x2-32cos2x+x2sin2x+C;
(13)12(x2-1)ln(x-1)-14x2-12x+C;
(14)x36+12x2sinx+xcosx-sinx+C;
(15)-1x(ln3x+3ln2x+6lnx+6)+C;
(16)-14xcos2x+18sin2x
+C;
(17)-12xcot2x-12x-12cotx+C;(18)12x2e
x2+C;
(19) xlnlnx+C;(20)(1+ex)ln(1+ex)-ex+C;
(21)12tanxsecx-12ln
secx+tanx+C;
(22)-ln(x+1+x22(1+x2)+x22+x2
+C;
(23)ex1+x+C;(24)x-121+x2earctanx+C.
习题5-4
(1)lnx+1x2-x+1+3arctan2x-13+C;
(2)x33+x22+x+8lnx-3lnx-1-4lnx+1+C;
(3) x-tanx+secx+C;
(4) 14lntanx2-18tan2x2+C.
习题6-1
1. 13(b3-a3)+b-a.
2. (1) 1;(2) 14πa2.
3.
(1) ∫10x2dx较大;
(2)∫10exdx较大.
4.
(1) 6≤∫41(x2+1)dx≤51;
(2)
π9≤∫31
3xarctanxdx≤23π;
(3) 2ae-a2<∫a-ae-x2dx<2a;(4)
-2e2≤∫02ex2-xdx≤-2e-1〖
〗4.
习题6-2
1. (1) 2x1+x4;
(2) x5e
-3x;
(3) (sinx-cosx)cos(πsin2x);(4)sinx-
xcosxx2.
2.
(1) -12;
(2)6;(3)2.
3. cosxsinx-1.
4. 当x=0时.
5.
(1) 23(8-33);
(2)16;(3)1+π8;(4)203.
6. -32.
习题6-3
1. (1) 0;(2) 51512;(
3) 16;(4) 14
;
(5)π6-38
;(6) 2(3-1);(7) 2-233;
(8) π2;
(9) 12ln32;
(10) ln2-13ln5;(11) 7
ln2-6ln(62+1);
(12) 43.
2. (1)0;(2) 0;(3) 32π.
习题6-4
2. (1) 1-2e;
(2) 14(e2+1);
(3)4(2ln2-1);(4)14-
133π+12ln32;
(5) 15(eπ-2);(6) 2-34
ln2;
(7)π36-π4;(8)12(esin1-ecos1+1);
(9)ln2-12;(10) 12-38ln3.
3. 0.
习题6-5
1. (1)1;(2) 2;(3) 4
3;(4) 76;
(5) 12+ln2;(6) 1
6;(7) e+1e-2;(
8) b-a.
2. (1) Vy=2π;
(2)Vx=1287
π,Vy=12.8π;
(3)Vy=310π;(4)Vx=pa2π;(5)
Vy=4π2.
3. (1)a=1e,(x0,y0)=(e2,1);
(2) S=16e2-12.
4.12ln2提示:
f(x)=0,
x1+x2, x≥0
x<0.
5.a=-4,b=6,c=0.
6.50;100.
7.
(1)Q=2.5,L=6.25;
(2)0.25.
8.96.73
习题6-6
1. (1) 13;(2) 发散;(3)1a;(4) 发散;
(5)发散;(6)π;(7) 83;(8) 1;
(9) π2;(10) -1;(11
) 发散;(12)1.
2. 当k>1时收敛于1(k-1)(ln2)12-1;
当k≤1时发散;当k=1-1lnln2时取得最小值.
3. n!
.
4. (1) π4;
(2)π2
5. In=-(2n)!
!
(2n+1)!
!
=22n(n!
)2〖
〗(2n+1)!
(n=0,1,2,…).
6. (1) 1nΓ1n;
(2)Γ(α+1);
(3) 1nΓm+1n;(4) 12Γn+1
2.
习题7-1
1. 略.
2.
(1)(a,b,-c),(-a,b,c),(a,-b,c);
(2)(a,-b,-c),(-a,b,-c),(-a,-b,c);
(3)(-a,-b,-c).
3. 坐标面:
(x0,y0,0),(0,y0,z0),(x0,0,z0);
坐标轴:
(x0,0,0),(0,y0,0),(0,0,z0).
4.x轴:
34,y轴:
41,z轴:
5.
5. (0,1,-2).
6. 略.
习题7-2
1. MA→=-12
(a+b);MB→=12(a-b);MC→=12(a+b);MD
→=12(b-a).
2. 略.
3. (2,1,1).
4. (16,0,-20).
5. M1M2→=(
1,-2,-2),M1M2→=3.
13,-23,-23或-13
,23,23.
习题7-3
1. (1)1;(2) 4;(3) 28.
2. (1) 3,5i+j+7k;
(2)-18,10i+2j+14k;
(3)-10i-2j-14k.
3. -32.
4. ±(62,82,0).
5. 14.
6. 略.
7. 45j-35
k或-45j+
35k.
8. ∠A=76°22′,∠B=79°2′,∠C=24°36′.
习题7-4
1. 3x-2y+5z-22=0.
2. 2x+9y-6z=121.
3. 略.
4. x+z-1=0.
5. x+y+z-2=0.
6. 2x+3y+z-6=0.
7.
(1) x=2;
(2) x+3y=0;(3) x-y=0.
8. 13,23,-2
3.
9. (1)互相垂直;
(2)互相平行;
(3)斜交(相交但不垂直).
习题7-5
1. (1) x-23=y-31
=z-11;
(2) x-31=y-42=z+4-1;
(3) x-21=y-20=z+1〖
〗0;(4) x2=y-31=z+23.
2. x+3-5=y=z-25, [JB({〗x=-3-5t,
y=t,
z=2+5t.
3. x-2=y-23=z-4〖
〗1.
4. x-21=y+22=z3
.
5. x-10=y+37=z+2〖
〗16.
6. 461,661,-361.
7. B=1,D=-9.
8. x-3-1=y-31=z
1.
9. φ=arcsin1310.
10. 4x-y-2z-1=0.
11. y-z+3=0,
x-y-z+1=0.
12. 5.
13. (1)垂直,
(2)平行,(3)重合.
习题7-6
1. (x+1)2+(y+3)2+(z-2)2=32.
2. 以点(1,-2,-1)为球心,半径等于6的球面.
3.
(1)x23+y24+z24=1; x23+y2
4+z23=1;
(2) x2-y2-z2=1; x2+y2-z2=1.
4. (1) 母线平行于z轴的椭圆柱面;
(2)母线平行于x轴的抛物
柱面;
(3)椭圆锥面;(4)旋转椭球面;
(5)双叶双曲面;(6)圆锥面.
5. 3y2-z2=16, 3x2+2z2=16
6. x2+y2+(1-