For the infinite rectangular pipe in Ex. 3.4, suppose the potential on the bottom (y = 0) and the two sides (x = ± b) is zero, but the potential on the top (y = a) is a nonzero constant V 0. Find the potential inside the pipe. [Note: This is a rotated version of Prob. 3.14(b), but set it up as in Ex. 3.4 using sinusoidal functions in y and hyperbolic in x. It is an unusual case in which k = 0 must be included.