For the cylindrical capacitor of Problem 1.6c, evaluate the variational upper bound of Problem 1.17b with the naive trial function, Ψ1(ρ)=(b−ρ)/(b−a). Compare the variational result with the exact result for b/a=1.5,2,3. Explain the trend of your results in terms of the functional form of Ψ1. An improved trial function is treated by Collin (pp. 275--277).