-2, x < 0 Verify that the piecewise-defined function y = { 2, x20 is a solution of the differential equation ry' - 2y = 0 on (-0, 0). Obtain the differential equations of the family of plane curves described as: (a) straight lines through the origin; (b) circles with center on the r-axis; (c) circles with fixed radius r, tangent to the r-axis; (d) parabolas with axis parallel to the r-axis with distance from vertex to focus fixed as a; and (e) cubics cy = 2(x - a) with a held fixed.