Exercise 11.  Find the temperature function [Graphics:Images/TemperaturesModHome_gr_550.gif] in the upper half-plane  [Graphics:Images/TemperaturesModHome_gr_551.gif],  

that satisfies the following boundary conditions (shown in Figure 11.31).

                    [Graphics:Images/TemperaturesModHome_gr_552.gif]  

Solution 11.

See text and/or instructor's solution manual.

Answer.   Consider the mapping  [Graphics:../Images/TemperaturesModHome_gr_553.gif]  and multiply the boundary values in Example 11.17 by  100  and construct

                    [Graphics:../Images/TemperaturesModHome_gr_554.gif].  

A Short Solution.   Map the upper half-plane  [Graphics:../Images/TemperaturesModHome_gr_555.gif] onto the lower half-plane  [Graphics:../Images/TemperaturesModHome_gr_556.gif] with the function   [Graphics:../Images/TemperaturesModHome_gr_557.gif].  

Notice that the function in Example 11.17 takes on the same boundary values in the lower half-plane, multiply this function by  100  

and consider  [Graphics:../Images/TemperaturesModHome_gr_558.gif],   then construct   [Graphics:../Images/TemperaturesModHome_gr_559.gif].  

More details for the solution.   

For computational purposes we can use the formulas for the real and imaginary parts of  [Graphics:../Images/TemperaturesModHome_gr_560.gif],  that were derived in Section 10.4.

                    [Graphics:../Images/TemperaturesModHome_gr_561.gif].  

In particular,

(10-26)         [Graphics:../Images/TemperaturesModHome_gr_562.gif].  

If an explicit solution is required, then we can use Formula (10-26) in Section 10.4 and write  

                    [Graphics:../Images/TemperaturesModHome_gr_563.gif],    

where the function  [Graphics:../Images/TemperaturesModHome_gr_564.gif]  has range values satisfying   [Graphics:../Images/TemperaturesModHome_gr_565.gif].  

Now make the substitution   [Graphics:../Images/TemperaturesModHome_gr_566.gif]   and  

                    [Graphics:../Images/TemperaturesModHome_gr_567.gif]    and    [Graphics:../Images/TemperaturesModHome_gr_568.gif].   

Thus,

                    [Graphics:../Images/TemperaturesModHome_gr_569.gif]    

Therefore,

                    [Graphics:../Images/TemperaturesModHome_gr_570.gif].  

 

We are really done.   

 

Aside.   We can graph the function   [Graphics:../Images/TemperaturesModHome_gr_571.gif].   

                     [Graphics:../Images/TemperaturesModHome_gr_572.gif]

                    A contour graph of the function   [Graphics:../Images/TemperaturesModHome_gr_573.gif],

                    where  [Graphics:../Images/TemperaturesModHome_gr_574.gif]   for   [Graphics:../Images/TemperaturesModHome_gr_575.gif].

 

                     [Graphics:../Images/TemperaturesModHome_gr_576.gif]

                    A graph of the function   [Graphics:../Images/TemperaturesModHome_gr_577.gif],   

                    [Graphics:../Images/TemperaturesModHome_gr_578.gif]  

 

















 

This solution is complements of the authors.

 



































 

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