-2, I < 0 2, r20 2. Verify that the piecewise-defined function y = { is a solution of the differential equation ry' - 2y = 0 on (-30, 0). 3. 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 = (r - a) with a held fixed.