Find the first five nonzero terms in the solution of the given initial value problem

(a) Find the first five nonzero terms in the solution of the given initial value problem.
(b) Plot the four-term and the five-term approximations to the solution on the same axes.
© From the plot in part
(b) estimate the interval in which the four-term approximation is reasonably accurate. y’’+xy’+2y=0,y(0)=4,y’(0)=−1