solve the given ini- tial-value problem. Use a graphing utility to graph the continuous function y(x). dy 37. + 2y = f(x), y(0) = 0, where dx 39. f(x) = dy 38. +y=f(x), y(0) = 1, where dx dy dx f(x) = [1, 0x3 0, x > 3 f(x) = 1, -1, + 2xy = f(x), y(0) = 2, where 0x1 x>1 0, 0x