() For each of the following differential equations, determine if the proposed function is a solution. a) Let C' and k be constants. Given the differential equation f'(t) = kf(t), the function f(t) = Cet is ? b) Given the differential equation d = -3y, the function y = 2e-3 is ? c) Given the differential equation f'(t) = 1 f(t), the function f(t) = -et is d) Given the differential equation dy = 2, the function y(t) = 3t is ? a solution. ?