The solution of the initial-value problem x²y'' + xy' + x²y = 0 y(0) = 1 y'(0) = 0 is called a Bessel function of order 0.
(a) Solve the initial-value problem to find a power series expansion for the Bessel function.
(b) Graph several Taylor polynomials until you reach one that looks like a good approximation to the Bessel function on the interval [-5, 5].