2.(a) Using the method of variation of parameters, find a particular solution of the nonhomogeneous system = r + 2y + 6t dt dy = 3r + 2y -t dt (b) Find a particular solution (atleast first five coefficients) of y" - (r + 1)y + z y = r along with the initial conditions y(0) = 1, y'(0) = 1, in terms of power series in r