We have determined that d dx x 2x dy 2x 20 x dx y dx 2x 20x dy 20y dx dy xy x Y dx Applying these derivatives and simplifying gives the following result d d d x 20 xy y 20 dx dx 2x 20y d dx dy dx d v 2ydy and 20 0 dx dx dy dx 0 0 dy 1 dx 0