Chapter H

Exercises H.1

  1. 1.

    T

  2. 2.

    F

  3. 3.

    sinxxcosx+C

  4. 4.

    exxex+C

  5. 5.

    x2cosx+2xsinx+2cosx+C

  6. 6.

    x3cosx+3x2sinx+6xcosx6sinx+C

  7. 7.

    1/2ex2+C

  8. 8.

    x3ex3x2ex+6xex6ex+C

  9. 9.

    12xe2xe2x4+C

  10. 10.

    12ex(sinxcosx)+C

  11. 11.

    1/5e2x(sinx+2cosx)+C

  12. 12.

    113e2x(2sin(3x)3cos(3x))+C

  13. 13.

    110e5x(sin(5x)+cos(5x))+C

  14. 14.

    12cos2x+C

  15. 15.

    1x2+xsin1(x)+C

  16. 16.

    xtan1(2x)14ln|4x2+1|+C

  17. 17.

    12x2tan1(x)x2+12tan1(x)+C

  18. 18.

    xcos1x1x2+C

  19. 19.

    12x2ln|x|x24+C

  20. 20.

    x24+12x2ln|x|2xln|x|+2x+C

  21. 21.

    x24+12x2ln|x1|x212ln|x1|+C

  22. 22.

    12x2ln(x2)x22+C

  23. 23.

    13x3ln|x|x39+C

  24. 24.

    2x+x(ln|x|)22xln|x|+C

  25. 25.

    2x+x(ln|x+1|)2+(ln|x+1|)22xln|x+1|2ln|x+1|+2+C

  26. 26.

    xtanx+ln|cosx|+C

  27. 27.

    ln|sinx|xcotx+C

  28. 28.

    25(x2)5/2+43(x2)3/2+C

  29. 29.

    13(x22)3/2+C

  30. 30.

    secx+C

  31. 31.

    xsecxln|secx+tanx|+C

  32. 32.

    xcscxln|cscx+cotx|+C

  33. 33.

    xsinhxcoshx+C

  34. 34.

    xcoshxsinhx+C

  35. 35.

    xsinh1xx2+1+C

  36. 36.

    xtanh1x+12ln|x21|+C

  37. 37.

    1/2x(sin(lnx)cos(lnx))+C

  38. 38.

    2sin(x)2xcos(x)+C

  39. 39.

    12xln|x|x2+C

  40. 40.

    2xex2ex+C

  41. 41.

    1/2x2+C

  42. 42.

    12ex2(x21)+C

  43. 43.

    π

  44. 44.

    2/e

  45. 45.

    0

  46. 46.

    3π2212

  47. 47.

    1/2

  48. 48.

    62e

  49. 49.

    34e254e4

  50. 50.

    12+eπ2

  51. 51.

    15(eπ+eπ)

  52. 52.

    313(1+e2π/3)+C

  53. 53.
  54. 54.

    • π(e2)

      π2(e2+1)

  55. 55.

    • bn=(1)n+12/n

      answers will vary

  56. 56.

    • bn=(1)(n1)/24/πn2 for odd n and bn=0 for even n

      answers will vary

Exercises H.2

  1. 1.

    F

  2. 2.

    F

  3. 3.

    F

  4. 4.

    F

  5. 5.

    14sin4x+C

  6. 6.

    12x+14sin2x+C

  7. 7.

    38x+14sin2x+132sin4x+C

  8. 8.

    15cos5x13cos3x+C

  9. 9.

    16cos6x14cos4x+C

  10. 10.

    111sin11x29sin9x+17sin7x+C

  11. 11.

    12cos2xln|cosx|+C

  12. 12.

    x8132sin(4x)+C

  13. 13.

    (27cos3x23cosx)cosx+C

  14. 14.

    12(13cos(3x)+cos(x))+C

  15. 15.

    12(14sin(4x)110sin(10x))+C

  16. 16.

    12(1πsin(πx)13πsin(3πx))+C

  17. 17.

    12(sin(x)+13sin(3x))+C

  18. 18.

    1πsin(π2x)+13πsin(πx)+C

  19. 19.

    tanxx+C

  20. 20.

    15tan5x+13tan3x+C

  21. 21.

    tan6(x)6+tan4x4+C

  22. 22.

    tan4(x)4+C

  23. 23.

    sec5(x)5sec3x3+C

  24. 24.

    sec9(x)92sec7x7+sec5x5+C

  25. 25.

    13tan3xtanx+x+C

  26. 26.

    14tanxsec3x+38(secxtanx+ln|secx+tanx|)+C

  27. 27.

    12(secxtanxln|secx+tanx|)+C

  28. 28.

    14tanxsec3x18(secxtanx+ln|secx+tanx|)+C

  29. 29.

    ln|cscxcotx|+C

  30. 30.

    13csc3x15csc5x+C

  31. 31.

    12cot2x+ln|cscx|+C

  32. 32.

    19cot9x17cot7x+C

  33. 33.

    25

  34. 34.

    0

  35. 35.

    32/315

  36. 36.

    1/2

  37. 37.

    2/3

  38. 38.

    1/5

  39. 39.

    16/15

  40. 40.

    3π3

  41. 41.

    1

Exercises H.3

  1. 1.

    backwards

  2. 2.

    5sinθ

  3. 3.

    • tan2θ+1=sec2θ

      9sec2θ.

  4. 4.

    Because we are considering a>0 and x=asinθ, which means θ=sin1(x/a). The arcsine function has a domain of π/2θπ/2; on this domain, cosθ0, so acosθ is always non-negative, allowing us to drop the absolute value signs.

  5. 5.

    12(xx2+1+ln|x2+1+x|)+C

  6. 6.

    12xx2112ln|x+x21|+C

  7. 7.

    xx2+1/4+14ln|2x2+1/4+2x|+C=12x4x2+1+14ln|4x2+1+2x|+C

  8. 8.

    16sin1(3x)+321/9x2+C=16sin1(3x)+1219x2+C

  9. 9.

    4(12xx21/16132ln|4x+4x21/16|)+C=12x16x2118ln|4x+16x21|+C

  10. 10.

    8ln|x2+22+x2|+C; with Section 7.4, we can state the answer as 8sinh1(x/2)+C.

  11. 11.

    3sin1(x7)+C (Trig. Subst. is not needed)

  12. 12.

    5ln|x8+x288|+C

  13. 13.

    2(x4x2+4+ln|x2+12+x2|)+C

  14. 14.

    12(sin1x+x1x2)+C

  15. 15.

    12(9sin1(x/3)+x9x2)+C

  16. 16.

    12xx2168ln|x4+x2164|+C

  17. 17.

    7tan1(x7)+C

  18. 18.

    3sin1(x3)+C

  19. 19.

    14sin1(x5)+C

  20. 20.

    23sec1(|x|/3)+C

  21. 21.

    54sec1(|x|/4)+C

  22. 22.

    12sin1(x2)+C

  23. 23.

    tan1(x17)7+C

  24. 24.

    2sin1(x34)+C

  25. 25.

    3sin1(x45)+C

  26. 26.

    tan1(x+35)+C

  27. 27.

    x21111sec1(x/11)+C

  28. 28.

    x23+C (Trig. Subst. is not needed)

  29. 29.

    1x2+9+C   (Trig. Subst. is not needed)

  30. 30.

    52xx210+25ln|x10+x21010|+C

  31. 31.

    118x+2x2+4x+13+154tan1(x+23)+C

  32. 32.

    x1x2sin1x+C

  33. 33.

    17(5x2xsin1(x/5))+C

  34. 34.

    12xx2+332ln|x2+33+x3|+C

  35. 35.

    π/2

  36. 36.

    1638ln(2+3)

  37. 37.

    22+2ln(1+2)

  38. 38.

    π/4+1/2)

  39. 39.

    9sin1(1/3)+22   Note: the new bounds of integration are sin1(1/3)<θ<sin1(1/3). The final answer comes with recognizing that sin1(1/3)=sin1(1/3) and that cos(sin1(1/3))=cos(sin1(1/3))=22/3.

  40. 40.

    π/8

  41. 41.

    • π(1π4)

      π(2ln(1+2))

Exercises H.4

  1. 1.

    rational

  2. 2.

    T

  3. 3.

    Ax+Bx3

  4. 4.

    Ax3+Bx+3

  5. 5.

    Ax7+Bx+7

  6. 6.

    Ax+Bx+Cx2+7

  7. 7.

    3ln|x2|+4ln|x+5|+C

  8. 8.

    9ln|x+1|2ln|x|+C

  9. 9.

    13(ln|x+2|ln|x2|)+C

  10. 10.

    ln|x+5|2x+5+C

  11. 11.

    4x+83ln|x+8|+C

  12. 12.

    5x+1+7ln|x|+2ln|x+1|+C

  13. 13.

    ln|2x3|+5ln|x1|+2ln|x+3|+C

  14. 14.

    15ln|5x1|+23ln|3x1|+37ln|7x+3|+C

  15. 15.

    x+ln|x1|ln|x+2|+C

  16. 16.

    x22+x+1259ln|x5|+649ln|x+4|+C

  17. 17.

    2x+C

  18. 18.

    16(ln|x2+2x+3|+2ln|x|2tan1(x+12))+C

  19. 19.

    1x+12ln|x1x+1|+C

  20. 20.

    32ln|x2+4x+10|+x+tan1(x+26)6+C

  21. 21.

    ln|3x2+5x1|+2ln|x+1|+C

  22. 22.

    2ln|x3|+2ln|x2+6x+10|4tan1(x+3)+C

  23. 23.

    ln|x|12ln(x2+1)tan1x12(x2+1)+C

  24. 24.

    910ln|x2+9|+15ln|x+1|415tan1(x3)+C

  25. 25.

    12(3ln|x2+2x+17|4ln|x7|+tan1(x+14))+C

  26. 26.

    12ln(x2+1)12tan1(x2)+C

  27. 27.

    14ln(x2+3)+14ln(x2+1)+C=14lnx2+1x2+3+C

  28. 28.

    12(x2+2x+4)239tan1(x+13)2(x+1)3(x2+2x+4)+C

  29. 29.

    3(ln|x22x+11|+ln|x9|)+325tan1(x110)+C

  30. 30.

    12ln|x2+10x+27|+5ln|x+2|62tan1(x+52)+C

  31. 31.

    132ln|x2|132ln|x+2|116tan1(x/2)+C

  32. 32.

    lnxln|x+1|+C

  33. 33.

    lnx12ln(x2+1)+121x2+1+C

  34. 34.

    tan1xxx2+1+C

  35. 35.

    ln(2000/243)2.108

  36. 36.

    5ln(9/4)13ln(17/2)3.3413

  37. 37.

    π/4+tan13ln(11/9)0.263

  38. 38.

    1/8

  39. 39.

Exercises H.5

  1. 1.

    xsin1x+1x2+C

  2. 2.

    16sin32x110sin52x+C

  3. 3.

    18ln|x2|9ln|x1|5ln|x3|+C

  4. 4.

    15sec5x+C

  5. 5.

    x25x2+25+C

  6. 6.

    2ln|24x2x|+4x2+C

  7. 7.

    2ln|x1|ln|x|1x11(x1)2+C

  8. 8.

    4+4xx2+2sin1(x28)+C

  9. 9.

    12ex2(x21)+C

  10. 10.

    3x+83+ln[x+832]2ln|(x+8)23+2x+83+4|63tan1x+83+13+C

  11. 11.

    113e2x(2sin3x3cos3x)+C

  12. 12.

    14sin4x16sin6x+C

  13. 13.

    4x2+C

  14. 14.

    13x3x2+3x12x14ln|x|234ln|x+2|+C

  15. 15.

    2tan1x+C

  16. 16.

    ln|secex+tanex|+C

  17. 17.

    127[6xsin3x(9x22)cos3x]+C

  18. 18.

    27cos7/2x23cos3/2x+C

  19. 19.

    23(1+ex)3/2+C

  20. 20.

    116[2x4x2+99ln(2x+4x2+9]+C

  21. 21.

    13tan3x+C

  22. 22.

    xcscx+ln|cscxcotx|+C

  23. 23.

    14(8x3)4/3+C

  24. 24.

    2sinx2xcosx+C

  25. 25.

    110(32x)5/212(32x)3/2+C

  26. 26.

    12e2xex+ln(1+ex)+C

  27. 27.

    25x5/283x3/2+6x1/2+C

  28. 28.

    13(16x2)3/216(16x2)1/2+C

  29. 29.

    112ln|x+5|152ln|x+7|+C

  30. 30.

    xtan15x110ln(1+25x2)+C

  31. 31.

    etanx+C

  32. 32.

    15ln|5x+7+5x2|+C

  33. 33.

    15cot5x+13cot3xcotxx+C

  34. 34.

    15(x225)5/2+253(x225)3/2+C

  35. 35.

    13x314tanh4x+C

  36. 36.

    14x2e4x18xe4x132e4x+C

  37. 37.

    3sin1(x+56)+C

  38. 38.

    ln(x+3)2(x2+9)2|x3|5+13tan1x3+C

  39. 39.

    13sec3xsecx+C

  40. 40.

    x3sinx+3x2cosx6xsinx6cosx+sinx+C

  41. 41.

    2sin1(2x3)1x94x2+C

  42. 42.

    24x103ln|sin3x|13cot3x+C

  43. 43.

    lnx+4x4+4ln|1x4|+C

  44. 44.

    21+cosx+C

  45. 45.

    x2(25+x2)+110tan1(x5)+C

  46. 46.

    ln(x2+4)32tan1x2+75tan1x5+C

  47. 47.

    14x42x2+4ln|x|+C

  48. 48.

    25x5/2lnx425x5/2+C

  49. 49.

    364(2x+3)8/3920(2x+3)5/3+2716(2x+3)2/3+C

  50. 50.

    exx+1+C

  51. 51.

    17cos7x+C

  52. 52.

    x22sin1x14sin1x+x41x2+C

  53. 53.
  54. 54.

    ln|1+tanθ2|ln|1tanθ2|+C

  55. 55.

    12ln|tanθ2|14tan2θ2+C.

Exercises H.6

  1. 1.

    The interval of integration is finite, and the integrand is continuous on that interval.

  2. 2.

    converge

  3. 3.

    converges; could also state 10.

  4. 4.

    p>1

  5. 5.

    p>1

  6. 6.

    p<1

  7. 7.

    e5/2

  8. 8.

    1/2

  9. 9.

    1/3

  10. 10.

    π/3

  11. 11.

    1/ln2

  12. 12.

    diverges

  13. 13.

    diverges

  14. 14.

    diverges

  15. 15.

    1

  16. 16.

    diverges

  17. 17.

    diverges

  18. 18.

    diverges

  19. 19.

    diverges

  20. 20.

    diverges

  21. 21.

    23

  22. 22.

    6

  23. 23.

    diverges

  24. 24.

    diverges

  25. 25.

    diverges

  26. 26.

    2+22

  27. 27.

    1

  28. 28.

    1/2

  29. 29.

    0

  30. 30.

    π/2

  31. 31.

    1/4

  32. 32.

    diverges

  33. 33.

    1

  34. 34.

    1

  35. 35.

    diverges

  36. 36.

    1/2

  37. 37.

    diverges; Limit Comparison Test with 1/x.

  38. 38.

    converges; Limit Comparison Test with 1/x3/2.

  39. 39.

    diverges; Limit Comparison Test with 1/x.

  40. 40.

    converges; Direct Comparison Test with xex.

  41. 41.

    converges; Direct Comparison Test with ex.

  42. 42.

    converges; Direct Comparison Test with xex.

  43. 43.

    converges; Direct Comparison Test with 1/(x21).

  44. 44.

    diverges; Direct Comparison Test with x/(x2+1).

  45. 45.

    converges; Direct Comparison Test with 1/ex.

  46. 46.

    converges; Limit Comparison Test with 1/ex.

  47. 47.

    • eλa

      1λ

      e1

  48. 48.

Exercises H.7

  1. 1.

    F

  2. 2.

    When the antiderivative cannot be computed and when the integrand is unknown.

  3. 3.

    They are superseded by the Trapezoidal Rule; it takes an equal amount of work and is generally more accurate.

  4. 4.

    It is superseded by the Trapezoidal Rule; it is about as accurate, but takes more work.

  5. 5.

    • 3/4

      2/3

      2/3

  6. 6.

    • 250

      250

      250

  7. 7.

    • 14(1+2)π1.896

      16(1+22)π2.005

      2

  8. 8.

    • 2+2+35.15

      2/3(3+2+23)5.25

      16/35.33

  9. 9.

    • 38.5781

      147/436.75

      147/436.75

  10. 10.

    • 0.2207

      0.2005

      1/5

  11. 11.

    • 0

      0

      0

  12. 12.

    • 9(1+3)/212.294

      3+6313.392

      9π/214.137

  13. 13.

    Trapezoidal Rule: 0.9006

    Simpson’s Rule: 0.90452

  14. 14.

    Trapezoidal Rule: 3.0241

    Simpson’s Rule: 2.9315

  15. 15.

    Trapezoidal Rule: 13.9604

    Simpson’s Rule: 13.9066

  16. 16.

    Trapezoidal Rule: 3.0695

    Simpson’s Rule: 3.14295

  17. 17.

    Trapezoidal Rule: 1.1703

    Simpson’s Rule: 1.1873

  18. 18.

    Trapezoidal Rule: 2.52971

    Simpson’s Rule: 2.5447

  19. 19.

    Trapezoidal Rule: 1.0803

    Simpson’s Rule: 1.077

  20. 20.

    Trapezoidal Rule: 3.5472

    Simpson’s Rule: 3.6133

  21. 21.

    • n=161 (using max(f′′(x))=1)

      n=12 (using max(f(4)(x))=1)

  22. 22.

    • n=150 (using max(f′′(x))=1)

      n=18 (using max(f(4)(x))=7)

  23. 23.

    • n=1004 (using max(f′′(x))=39)

      n=62 (using max(f(4)(x))=800)

  24. 24.

    • n=5591 (using max(f′′(x))=300)

      n=46 (using max(f(4)(x))=24)

  25. 25.

    • Area is 30.8667 cm2.

      Area is 308,667 yd2.

  26. 26.

    • Area is 25.0667 cm2

      Area is 250,667 yd2

  27. 27.

    Let f(x)=a(xx1)2+b(xx1)+c, so that f(x1)=c=y1, f(x1+Δx)=aΔx2+bΔx+c=y2, and f(x1+2Δx)=4aΔx2+2bΔx+c=y3. Therefore, a=y12y2+y32(Δx)2 and b=4y2y33y12Δx, and x1x1+2Δxa(xx1)2+b(xx1)+cdx=a(2Δx)33+b(2Δx)22+c(2Δx)=4(y12y2+y3)Δx3+(4y2y33y1)Δx+2y1Δx=Δx3(4y18y2+4y3+12y23y39y1+6y1)=Δx3(y1+4y2+y3).

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