In each of Problems 4 through 6, determine a lower bound for the
radius of convergence of series solutions about each given point xₒ
for the given differential equation.
4. y"+ 4y' + 6xy = 0; x₀ = 0, x0 = 4
5. (x²-2x-3)y" +xy'+4y = 0; x₀ = 4, x₀ = - 4, x₀ = 0
6. (1+x³)y" + 4xy' + y = 0; x₀ = 0, x₀ = 2