Answer to Problem 61

Using the plus sign in (6.8 ) gives



Equation 125

Then



Equation 126

which says that as .

But this contradicts the boundary condition that at .

Therefore (6.7+) does not represent a solution of the boundary value problem (BVP).

Using the minus sign in (6.8 ) gives



Equation 127

Then



Equation 128

which says that as , in agreement with the boundary condition .

Thus it follows that equation (6.7-) gives



Equation 129

with p given by (6.6), as the correct solution of the BVP.