Exercise 12.  Find the temperature function [Graphics:Images/TemperaturesModHome_gr_579.gif] in the first quadrant  [Graphics:Images/TemperaturesModHome_gr_580.gif],  

that satisfies the following boundary conditions (shown in Figure 11.32).  

                    [Graphics:Images/TemperaturesModHome_gr_581.gif]  

Solution 12.

See text and/or instructor's solution manual.

Answer.   [Graphics:../Images/TemperaturesModHome_gr_582.gif].  

Solution.   Carefully look at Example 11.17 and discover that   [Graphics:../Images/TemperaturesModHome_gr_583.gif]   has the boundary values

                    [Graphics:../Images/TemperaturesModHome_gr_584.gif]      

Hence, if we use the rotation  [Graphics:../Images/TemperaturesModHome_gr_585.gif]  we see that   [Graphics:../Images/TemperaturesModHome_gr_586.gif]   has the boundary values

                    [Graphics:../Images/TemperaturesModHome_gr_587.gif]  

Therefore the solution we seek is  

                    [Graphics:../Images/TemperaturesModHome_gr_588.gif]     

Therefore,   

                    [Graphics:../Images/TemperaturesModHome_gr_589.gif].

For computational purposes we can use the formulas for the real and imaginary parts of  [Graphics:../Images/TemperaturesModHome_gr_590.gif],  that were derived in Section 10.4.

                    [Graphics:../Images/TemperaturesModHome_gr_591.gif].  

In particular,

(10-26)         [Graphics:../Images/TemperaturesModHome_gr_592.gif].  

Now make the substitution   [Graphics:../Images/TemperaturesModHome_gr_593.gif]   and  

                    [Graphics:../Images/TemperaturesModHome_gr_594.gif]    and    [Graphics:../Images/TemperaturesModHome_gr_595.gif].   

Thus,  

                    [Graphics:../Images/TemperaturesModHome_gr_596.gif]   

Therefore,

                    [Graphics:../Images/TemperaturesModHome_gr_597.gif].  

 

We are done.   

 

Aside.   We can graph the function   [Graphics:../Images/TemperaturesModHome_gr_598.gif].   

                     

[Graphics:../Images/TemperaturesModHome_gr_599.gif]

  

                    A contour graph of the function   [Graphics:../Images/TemperaturesModHome_gr_600.gif],

                    where  [Graphics:../Images/TemperaturesModHome_gr_601.gif]   for   [Graphics:../Images/TemperaturesModHome_gr_602.gif].

                     

[Graphics:../Images/TemperaturesModHome_gr_603.gif]

  

                    A contour graph of the function   [Graphics:../Images/TemperaturesModHome_gr_604.gif],    

                    [Graphics:../Images/TemperaturesModHome_gr_605.gif]  

 

We are really done.   

 

Aside.   We can check out some of the boundary values of   [Graphics:../Images/TemperaturesModHome_gr_606.gif].   

[Graphics:../Images/TemperaturesModHome_gr_607.gif]


[Graphics:../Images/TemperaturesModHome_gr_608.gif]

[Graphics:../Images/TemperaturesModHome_gr_609.gif]
[Graphics:../Images/TemperaturesModHome_gr_610.gif]

[Graphics:../Images/TemperaturesModHome_gr_611.gif]

[Graphics:../Images/TemperaturesModHome_gr_612.gif]

[Graphics:../Images/TemperaturesModHome_gr_613.gif]

[Graphics:../Images/TemperaturesModHome_gr_614.gif]

[Graphics:../Images/TemperaturesModHome_gr_615.gif]

[Graphics:../Images/TemperaturesModHome_gr_616.gif]

[Graphics:../Images/TemperaturesModHome_gr_617.gif]
[Graphics:../Images/TemperaturesModHome_gr_618.gif]


[Graphics:../Images/TemperaturesModHome_gr_619.gif]
[Graphics:../Images/TemperaturesModHome_gr_620.gif]
[Graphics:../Images/TemperaturesModHome_gr_621.gif]


[Graphics:../Images/TemperaturesModHome_gr_622.gif]

[Graphics:../Images/TemperaturesModHome_gr_623.gif]

[Graphics:../Images/TemperaturesModHome_gr_624.gif]



















This solution is complements of the authors.

 



































 

(c) 2008 John H. Mathews, Russell W. Howell