Solution 2.
See text and/or instructor's solution manual.
Answer.
.
Alternative
Answer.
.
Solution. Use
the Poisson's integral formula, Equation
(11-12)
, and
obtain
Using techniques from calculus we have the integration formulas
, and
, and
.
We obtain the solution as follows
The function
is continuous in the upper half-plane, and on the boundary
,
except at the discontinuities
and
on
the real axis.
We are done.
Aside. We can let Mathematica double check our work.
Using the identities
,
,
and Log
, will
convert Mathematica's solution into the desired
form:
.
We are really done.
Aside. For
illustration purposes we can graph the function
.
![[Graphics:../Images/PoissonIntegralModHome_gr_76.gif]](../Images/PoissonIntegralModHome_gr_76.gif)
A
contour graph of ![]()
for
.
![[Graphics:../Images/PoissonIntegralModHome_gr_80.gif]](../Images/PoissonIntegralModHome_gr_80.gif)
A
contour graph of ![]()
for
.
![[Graphics:../Images/PoissonIntegralModHome_gr_84.gif]](../Images/PoissonIntegralModHome_gr_84.gif)
A
contour graph of ![]()
![[Graphics:../Images/PoissonIntegralModHome_gr_86.gif]](../Images/PoissonIntegralModHome_gr_86.gif)
We are really really done.
Aside. We can let Mathematica check out some boundary values.
We are really really really done.
The Alternative Solution.
From Example
11.12, the function
is harmonic in the upper half-plane
, which
takes on the boundary values
![[Graphics:../Images/PoissonIntegralModHome_gr_102.gif]](../Images/PoissonIntegralModHome_gr_102.gif)
A
graph of the
terms
.
Using techniques from Section
11.2, we find that the function
is harmonic in the upper half-plane and has the boundary
values
,
, and
![[Graphics:../Images/PoissonIntegralModHome_gr_108.gif]](../Images/PoissonIntegralModHome_gr_108.gif)
A
graph of the
terms
.
This function can be added to the function
in Example 11.12 to get
![[Graphics:../Images/PoissonIntegralModHome_gr_112.gif]](../Images/PoissonIntegralModHome_gr_112.gif)
![[Graphics:../Images/PoissonIntegralModHome_gr_113.gif]](../Images/PoissonIntegralModHome_gr_113.gif)
A
graph of the intermediate
function
.
Adjust the variables in
and rescale the output to obtain the desired solution
![[Graphics:../Images/PoissonIntegralModHome_gr_117.gif]](../Images/PoissonIntegralModHome_gr_117.gif)
Graph Of The Alternative
Solution. For illustration purposes we
can graph the alternative
solution
.
![[Graphics:../Images/PoissonIntegralModHome_gr_119.gif]](../Images/PoissonIntegralModHome_gr_119.gif)
A
contour graph of the alternative
solution
for
.
![[Graphics:../Images/PoissonIntegralModHome_gr_123.gif]](../Images/PoissonIntegralModHome_gr_123.gif)
A
contour graph of the alternative
solution
for
.
![[Graphics:../Images/PoissonIntegralModHome_gr_127.gif]](../Images/PoissonIntegralModHome_gr_127.gif)
A
graph of the alternative
solution ![]()
![[Graphics:../Images/PoissonIntegralModHome_gr_129.gif]](../Images/PoissonIntegralModHome_gr_129.gif)
This solution is complements of the authors.
(c) 2008 John H. Mathews, Russell W. Howell