For these stream functions, determine if a potential function exists, find the potential function if it does, and determine if the Laplace equation in o is satisfied: (a) = 3xy + 2x; (b) = 3xy + 2x. For these stream functions, determine if a potential function exists, find the potential function if it does, and determine if the Laplace equation in o is satisfied: (a) = 6xy; (b) = xsin y.