Consider the differential equation dxdy=ky, where k is a non-zero constant.
(a) Solve the differential equation subject to the initial condition y(0)=A, where A>0.
(b) Show that for any two positive initial values A1=A2, the graphs of the corresponding solutions do not intersect.
(c) Explain, using the obtained solution, how the sign of k affects the behaviour of y as x increases without bound.