Then it may be seen that xy' = dy/dt and (x^2)y'' = (d^2/dt^2)y (dy/dt) The equation becomes (D^2 2D 1)y = (1e^t)^(2), where the operator D denotes differentiation with respect to t The homogeneous equation corresponding to the above equation is (D^2 2D 1)y = 0,