Callahan
    5.2: 1, 2, 4, 6
    7.3: 13, 16, 33
    9.1: 31, 32

[Graphics:Images/calculus_gr_1.gif]

1)  Find the partial derivatives of the following functions:

    a)  [Graphics:Images/calculus_gr_2.gif]:

[Graphics:Images/calculus_gr_3.gif]
[Graphics:Images/calculus_gr_4.gif]

    b)  [Graphics:Images/calculus_gr_5.gif]:

[Graphics:Images/calculus_gr_6.gif]
[Graphics:Images/calculus_gr_7.gif]
[Graphics:Images/calculus_gr_8.gif]
[Graphics:Images/calculus_gr_9.gif]

    c)  [Graphics:Images/calculus_gr_10.gif]:

[Graphics:Images/calculus_gr_11.gif]
[Graphics:Images/calculus_gr_12.gif]
[Graphics:Images/calculus_gr_13.gif]
[Graphics:Images/calculus_gr_14.gif]

    d)  [Graphics:Images/calculus_gr_15.gif]:

[Graphics:Images/calculus_gr_16.gif]
[Graphics:Images/calculus_gr_17.gif]
[Graphics:Images/calculus_gr_18.gif]

    e)  [Graphics:Images/calculus_gr_19.gif]:

[Graphics:Images/calculus_gr_20.gif]
[Graphics:Images/calculus_gr_21.gif]
[Graphics:Images/calculus_gr_22.gif]
[Graphics:Images/calculus_gr_23.gif]
[Graphics:Images/calculus_gr_24.gif]
[Graphics:Images/calculus_gr_25.gif]
[Graphics:Images/calculus_gr_26.gif]

    f)  [Graphics:Images/calculus_gr_27.gif]:

[Graphics:Images/calculus_gr_28.gif]
[Graphics:Images/calculus_gr_29.gif]
[Graphics:Images/calculus_gr_30.gif]
[Graphics:Images/calculus_gr_31.gif]
[Graphics:Images/calculus_gr_32.gif]

2)

    a)  Suppose [Graphics:Images/calculus_gr_33.gif].  Find [Graphics:Images/calculus_gr_34.gif] and [Graphics:Images/calculus_gr_35.gif]:

[Graphics:Images/calculus_gr_36.gif]
[Graphics:Images/calculus_gr_37.gif]
[Graphics:Images/calculus_gr_38.gif]
[Graphics:Images/calculus_gr_39.gif]
[Graphics:Images/calculus_gr_40.gif]
[Graphics:Images/calculus_gr_41.gif]

    b)  Find a point [Graphics:Images/calculus_gr_42.gif] at which [Graphics:Images/calculus_gr_43.gif].  At such a point a small change in [Graphics:Images/calculus_gr_44.gif] leaves the value of [Graphics:Images/calculus_gr_45.gif] virtually unchanged.

[Graphics:Images/calculus_gr_46.gif]

    So, any point on the line:

[Graphics:Images/calculus_gr_47.gif]

    Satisfies [Graphics:Images/calculus_gr_48.gif].  One example is, [Graphics:Images/calculus_gr_49.gif].

    c)  Find a point [Graphics:Images/calculus_gr_50.gif] at which a small increase in the x-value produces the same change in [Graphics:Images/calculus_gr_51.gif] as would the same-sized decrease in the y-value.

    In other words, find a point at which the rate of change of [Graphics:Images/calculus_gr_52.gif] with respect to [Graphics:Images/calculus_gr_53.gif] is the negative of the rate of change of [Graphics:Images/calculus_gr_54.gif] with respect to [Graphics:Images/calculus_gr_55.gif].

[Graphics:Images/calculus_gr_56.gif]
[Graphics:Images/calculus_gr_57.gif]
[Graphics:Images/calculus_gr_58.gif]
[Graphics:Images/calculus_gr_59.gif]

    So, any point on the line:

[Graphics:Images/calculus_gr_60.gif]
[Graphics:Images/calculus_gr_61.gif]

4)  The second partial derivatives of [Graphics:Images/calculus_gr_62.gif] are the partial derivatives of [Graphics:Images/calculus_gr_63.gif] and  [Graphics:Images/calculus_gr_64.gif].  Find the four second partial derivatives of the following functions:

    a)  [Graphics:Images/calculus_gr_65.gif]:

[Graphics:Images/calculus_gr_66.gif]
[Graphics:Images/calculus_gr_67.gif]
[Graphics:Images/calculus_gr_68.gif]
[Graphics:Images/calculus_gr_69.gif]
[Graphics:Images/calculus_gr_70.gif]
[Graphics:Images/calculus_gr_71.gif]

    b)  [Graphics:Images/calculus_gr_72.gif]:

[Graphics:Images/calculus_gr_73.gif]
[Graphics:Images/calculus_gr_74.gif]
[Graphics:Images/calculus_gr_75.gif]
[Graphics:Images/calculus_gr_76.gif]
[Graphics:Images/calculus_gr_77.gif]
[Graphics:Images/calculus_gr_78.gif]
[Graphics:Images/calculus_gr_79.gif]
[Graphics:Images/calculus_gr_80.gif]

    c)  [Graphics:Images/calculus_gr_81.gif]:

[Graphics:Images/calculus_gr_82.gif]
[Graphics:Images/calculus_gr_83.gif]
[Graphics:Images/calculus_gr_84.gif]
[Graphics:Images/calculus_gr_85.gif]
[Graphics:Images/calculus_gr_86.gif]
[Graphics:Images/calculus_gr_87.gif]
[Graphics:Images/calculus_gr_88.gif]
[Graphics:Images/calculus_gr_89.gif]
[Graphics:Images/calculus_gr_90.gif]
[Graphics:Images/calculus_gr_91.gif]

    d)  [Graphics:Images/calculus_gr_92.gif]:

[Graphics:Images/calculus_gr_93.gif]
[Graphics:Images/calculus_gr_94.gif]
[Graphics:Images/calculus_gr_95.gif]
[Graphics:Images/calculus_gr_96.gif]
[Graphics:Images/calculus_gr_97.gif]
[Graphics:Images/calculus_gr_98.gif]
[Graphics:Images/calculus_gr_99.gif]
[Graphics:Images/calculus_gr_100.gif]
[Graphics:Images/calculus_gr_101.gif]

    e)  [Graphics:Images/calculus_gr_102.gif]:

[Graphics:Images/calculus_gr_103.gif]
[Graphics:Images/calculus_gr_104.gif]
[Graphics:Images/calculus_gr_105.gif]
[Graphics:Images/calculus_gr_106.gif]
[Graphics:Images/calculus_gr_107.gif]
[Graphics:Images/calculus_gr_108.gif]
[Graphics:Images/calculus_gr_109.gif]
[Graphics:Images/calculus_gr_110.gif]
[Graphics:Images/calculus_gr_111.gif]
[Graphics:Images/calculus_gr_112.gif]
[Graphics:Images/calculus_gr_113.gif]

6)  Show that the function [Graphics:Images/calculus_gr_114.gif] satisfies the partial differential equation:

[Graphics:Images/calculus_gr_115.gif]

    To find [Graphics:Images/calculus_gr_116.gif]:

[Graphics:Images/calculus_gr_117.gif]
[Graphics:Images/calculus_gr_118.gif]
[Graphics:Images/calculus_gr_119.gif]

    To find [Graphics:Images/calculus_gr_120.gif]:

[Graphics:Images/calculus_gr_121.gif]
[Graphics:Images/calculus_gr_122.gif]
[Graphics:Images/calculus_gr_123.gif]

    To find [Graphics:Images/calculus_gr_124.gif]:

[Graphics:Images/calculus_gr_125.gif]
[Graphics:Images/calculus_gr_126.gif]
[Graphics:Images/calculus_gr_127.gif]

    So it is a solution!

[Graphics:Images/calculus_gr_128.gif]

    7.3: 13, 16, 33

[Graphics:Images/calculus_gr_129.gif]

[Graphics:Images/calculus_gr_130.gif]

[Graphics:Images/calculus_gr_131.gif]

[Graphics:Images/calculus_gr_132.gif]

[Graphics:Images/calculus_gr_133.gif]

[Graphics:Images/calculus_gr_134.gif]

[Graphics:Images/calculus_gr_135.gif]

    9.1: 31, 32

[Graphics:Images/calculus_gr_136.gif]

[Graphics:Images/calculus_gr_137.gif]

[Graphics:Images/calculus_gr_138.gif]


Converted by Mathematica      April 27, 2004