Consider steady incompressible, laminar flow of a Newtonian fluid in an infinitely long round pipe annulus of inner radius Ri and outer radius Ro. Ignore gravity effects. A constant negative pressure gradient is applied in the x-direction, (P2 - P1)/(x2 - x1), where x2 and x1 are two arbitrary locations along the x-axis, and P1 and P2 are the pressures at those two locations. In addition, there is an axial Couette flow with the outer cylinder moving at a constant x-direction speed Uo and the inner cylinder stationary. Derive the velocity distribution u(r) and plot it.