Callahan
5.2: 1, 2, 4, 6
7.3: 13, 16, 33
9.1: 31, 32
![[Graphics:Images/calculus_gr_1.gif]](Images/calculus_gr_1.gif)
1) Find the partial derivatives of the following functions:
a) :
![[Graphics:Images/calculus_gr_3.gif]](Images/calculus_gr_3.gif)
![[Graphics:Images/calculus_gr_4.gif]](Images/calculus_gr_4.gif)
b) :
![[Graphics:Images/calculus_gr_6.gif]](Images/calculus_gr_6.gif)
![[Graphics:Images/calculus_gr_7.gif]](Images/calculus_gr_7.gif)
![[Graphics:Images/calculus_gr_8.gif]](Images/calculus_gr_8.gif)
![[Graphics:Images/calculus_gr_9.gif]](Images/calculus_gr_9.gif)
c) :
![[Graphics:Images/calculus_gr_11.gif]](Images/calculus_gr_11.gif)
![[Graphics:Images/calculus_gr_12.gif]](Images/calculus_gr_12.gif)
![[Graphics:Images/calculus_gr_13.gif]](Images/calculus_gr_13.gif)
![[Graphics:Images/calculus_gr_14.gif]](Images/calculus_gr_14.gif)
d) :
![[Graphics:Images/calculus_gr_16.gif]](Images/calculus_gr_16.gif)
![[Graphics:Images/calculus_gr_17.gif]](Images/calculus_gr_17.gif)
![[Graphics:Images/calculus_gr_18.gif]](Images/calculus_gr_18.gif)
e) :
![[Graphics:Images/calculus_gr_20.gif]](Images/calculus_gr_20.gif)
![[Graphics:Images/calculus_gr_21.gif]](Images/calculus_gr_21.gif)
![[Graphics:Images/calculus_gr_22.gif]](Images/calculus_gr_22.gif)
![[Graphics:Images/calculus_gr_23.gif]](Images/calculus_gr_23.gif)
![[Graphics:Images/calculus_gr_24.gif]](Images/calculus_gr_24.gif)
![[Graphics:Images/calculus_gr_25.gif]](Images/calculus_gr_25.gif)
![[Graphics:Images/calculus_gr_26.gif]](Images/calculus_gr_26.gif)
f) :
![[Graphics:Images/calculus_gr_28.gif]](Images/calculus_gr_28.gif)
![[Graphics:Images/calculus_gr_29.gif]](Images/calculus_gr_29.gif)
![[Graphics:Images/calculus_gr_30.gif]](Images/calculus_gr_30.gif)
![[Graphics:Images/calculus_gr_31.gif]](Images/calculus_gr_31.gif)
![[Graphics:Images/calculus_gr_32.gif]](Images/calculus_gr_32.gif)
2)
a) Suppose . Find
and
:
![[Graphics:Images/calculus_gr_36.gif]](Images/calculus_gr_36.gif)
![[Graphics:Images/calculus_gr_37.gif]](Images/calculus_gr_37.gif)
![[Graphics:Images/calculus_gr_38.gif]](Images/calculus_gr_38.gif)
![[Graphics:Images/calculus_gr_39.gif]](Images/calculus_gr_39.gif)
![[Graphics:Images/calculus_gr_40.gif]](Images/calculus_gr_40.gif)
![[Graphics:Images/calculus_gr_41.gif]](Images/calculus_gr_41.gif)
b) Find a point at which
. At such a point a small change in
leaves the value of
virtually unchanged.
![[Graphics:Images/calculus_gr_46.gif]](Images/calculus_gr_46.gif)
So, any point on the line:
![[Graphics:Images/calculus_gr_47.gif]](Images/calculus_gr_47.gif)
Satisfies . One example is,
.
c) Find a point at which a small increase in the x-value produces the same change in
as would the same-sized decrease in the y-value.
In other words, find a point at which the rate of change of with respect to
is the negative of the rate of change of
with respect to
.
![[Graphics:Images/calculus_gr_56.gif]](Images/calculus_gr_56.gif)
![[Graphics:Images/calculus_gr_57.gif]](Images/calculus_gr_57.gif)
![[Graphics:Images/calculus_gr_58.gif]](Images/calculus_gr_58.gif)
![[Graphics:Images/calculus_gr_59.gif]](Images/calculus_gr_59.gif)
So, any point on the line:
![[Graphics:Images/calculus_gr_60.gif]](Images/calculus_gr_60.gif)
![[Graphics:Images/calculus_gr_61.gif]](Images/calculus_gr_61.gif)
4) The second partial derivatives of are the partial derivatives of
and
. Find the four second partial derivatives of the following functions:
a) :
![[Graphics:Images/calculus_gr_66.gif]](Images/calculus_gr_66.gif)
![[Graphics:Images/calculus_gr_67.gif]](Images/calculus_gr_67.gif)
![[Graphics:Images/calculus_gr_68.gif]](Images/calculus_gr_68.gif)
![[Graphics:Images/calculus_gr_69.gif]](Images/calculus_gr_69.gif)
![[Graphics:Images/calculus_gr_70.gif]](Images/calculus_gr_70.gif)
![[Graphics:Images/calculus_gr_71.gif]](Images/calculus_gr_71.gif)
b) :
![[Graphics:Images/calculus_gr_73.gif]](Images/calculus_gr_73.gif)
![[Graphics:Images/calculus_gr_74.gif]](Images/calculus_gr_74.gif)
![[Graphics:Images/calculus_gr_75.gif]](Images/calculus_gr_75.gif)
![[Graphics:Images/calculus_gr_76.gif]](Images/calculus_gr_76.gif)
![[Graphics:Images/calculus_gr_77.gif]](Images/calculus_gr_77.gif)
![[Graphics:Images/calculus_gr_78.gif]](Images/calculus_gr_78.gif)
![[Graphics:Images/calculus_gr_79.gif]](Images/calculus_gr_79.gif)
![[Graphics:Images/calculus_gr_80.gif]](Images/calculus_gr_80.gif)
c) :
![[Graphics:Images/calculus_gr_82.gif]](Images/calculus_gr_82.gif)
![[Graphics:Images/calculus_gr_83.gif]](Images/calculus_gr_83.gif)
![[Graphics:Images/calculus_gr_84.gif]](Images/calculus_gr_84.gif)
![[Graphics:Images/calculus_gr_85.gif]](Images/calculus_gr_85.gif)
![[Graphics:Images/calculus_gr_86.gif]](Images/calculus_gr_86.gif)
![[Graphics:Images/calculus_gr_87.gif]](Images/calculus_gr_87.gif)
![[Graphics:Images/calculus_gr_88.gif]](Images/calculus_gr_88.gif)
![[Graphics:Images/calculus_gr_89.gif]](Images/calculus_gr_89.gif)
![[Graphics:Images/calculus_gr_90.gif]](Images/calculus_gr_90.gif)
![[Graphics:Images/calculus_gr_91.gif]](Images/calculus_gr_91.gif)
d) :
![[Graphics:Images/calculus_gr_93.gif]](Images/calculus_gr_93.gif)
![[Graphics:Images/calculus_gr_94.gif]](Images/calculus_gr_94.gif)
![[Graphics:Images/calculus_gr_95.gif]](Images/calculus_gr_95.gif)
![[Graphics:Images/calculus_gr_96.gif]](Images/calculus_gr_96.gif)
![[Graphics:Images/calculus_gr_97.gif]](Images/calculus_gr_97.gif)
![[Graphics:Images/calculus_gr_98.gif]](Images/calculus_gr_98.gif)
![[Graphics:Images/calculus_gr_99.gif]](Images/calculus_gr_99.gif)
![[Graphics:Images/calculus_gr_100.gif]](Images/calculus_gr_100.gif)
![[Graphics:Images/calculus_gr_101.gif]](Images/calculus_gr_101.gif)
e) :
![[Graphics:Images/calculus_gr_103.gif]](Images/calculus_gr_103.gif)
![[Graphics:Images/calculus_gr_104.gif]](Images/calculus_gr_104.gif)
![[Graphics:Images/calculus_gr_105.gif]](Images/calculus_gr_105.gif)
![[Graphics:Images/calculus_gr_106.gif]](Images/calculus_gr_106.gif)
![[Graphics:Images/calculus_gr_107.gif]](Images/calculus_gr_107.gif)
![[Graphics:Images/calculus_gr_108.gif]](Images/calculus_gr_108.gif)
![[Graphics:Images/calculus_gr_109.gif]](Images/calculus_gr_109.gif)
![[Graphics:Images/calculus_gr_110.gif]](Images/calculus_gr_110.gif)
![[Graphics:Images/calculus_gr_111.gif]](Images/calculus_gr_111.gif)
![[Graphics:Images/calculus_gr_112.gif]](Images/calculus_gr_112.gif)
![[Graphics:Images/calculus_gr_113.gif]](Images/calculus_gr_113.gif)
6) Show that the function satisfies the partial differential equation:
![[Graphics:Images/calculus_gr_115.gif]](Images/calculus_gr_115.gif)
To find :
![[Graphics:Images/calculus_gr_117.gif]](Images/calculus_gr_117.gif)
![[Graphics:Images/calculus_gr_118.gif]](Images/calculus_gr_118.gif)
![[Graphics:Images/calculus_gr_119.gif]](Images/calculus_gr_119.gif)
To find :
![[Graphics:Images/calculus_gr_121.gif]](Images/calculus_gr_121.gif)
![[Graphics:Images/calculus_gr_122.gif]](Images/calculus_gr_122.gif)
![[Graphics:Images/calculus_gr_123.gif]](Images/calculus_gr_123.gif)
To find :
![[Graphics:Images/calculus_gr_125.gif]](Images/calculus_gr_125.gif)
![[Graphics:Images/calculus_gr_126.gif]](Images/calculus_gr_126.gif)
![[Graphics:Images/calculus_gr_127.gif]](Images/calculus_gr_127.gif)
So it is a solution!
![[Graphics:Images/calculus_gr_128.gif]](Images/calculus_gr_128.gif)
7.3: 13, 16, 33
![[Graphics:Images/calculus_gr_130.gif]](Images/calculus_gr_130.gif)
![[Graphics:Images/calculus_gr_133.gif]](Images/calculus_gr_133.gif)
![[Graphics:Images/calculus_gr_135.gif]](Images/calculus_gr_135.gif)
9.1: 31, 32
![[Graphics:Images/calculus_gr_137.gif]](Images/calculus_gr_137.gif)