276 Difference Schemes for Elliptic Equations
In a similar way we find that
etc. By means of the method of separation of variables problern (8) reduces
to the two one-dimensional eigenvalue problen1s for p(x 1 ) = p(i 1 h 1 ) and
TJ(x2) = TJ(i2 h2):
Px 1 x 1 + >, (i l P--^0 >
(_,,_ r"'X1 + l 2 h I ;,(^1 l,,) ,,., I I --o. )
X1= 1
Their solutions have been already found in Chapter 2, Section 3.
Along these lines, we can in1mediately write down the eigenvalues and
the orthonormal eigenfunctions
(9)
(10)
where
;,(!) 0 = ;,(2) 0 = 0)
(11)