Extra Example 2.  Use Poisson's Integral formula to find the harmonic function [Graphics:Images/PoissonIntegralMod_gr_103.gif] that is harmonic in the upper half-plane [Graphics:Images/PoissonIntegralMod_gr_104.gif], that takes on the boundary values  

            [Graphics:Images/PoissonIntegralMod_gr_105.gif]  

Explore Extra Solution 2.

[Graphics:../Images/PoissonIntegralMod_gr_107.gif]



[Graphics:../Images/PoissonIntegralMod_gr_108.gif]

 

 

 

Use Mathematica to make a contour plot of the solution.

[Graphics:../Images/PoissonIntegralMod_gr_109.gif]





[Graphics:../Images/PoissonIntegralMod_gr_110.gif]

[Graphics:../Images/PoissonIntegralMod_gr_111.gif]

 

 

 

Then use Mathematica to make a 3D plot of the solution.

[Graphics:../Images/PoissonIntegralMod_gr_112.gif]





[Graphics:../Images/PoissonIntegralMod_gr_113.gif]

[Graphics:../Images/PoissonIntegralMod_gr_114.gif]

Therefore, the function [Graphics:../Images/PoissonIntegralMod_gr_115.gif] is harmonic in the upper half-plane  [Graphics:../Images/PoissonIntegralMod_gr_116.gif],  and takes on the desired boundary values.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) 2006 John H. Mathews, Russell W. Howell