Solve 2v + r rr p2 1 V 8v + Oz2 = 0, z2 - where r = [0, 1] and z = [0, 1], subject to boundary conditions v(0, z) = v(1, z) = v(r, I') = 0 and v(r, 0) = r, numerically using second-order centered finite differences for I = 0.5, 1.0 and 2.5. =