y" + (1/x2)y' - (1/x3)y = 0
a) Show that x = 0 is an irregular singular point
b) Use the fact that y1 = x is a solution to find a second independent solution y2 by the method discussed earlier in the book.
c) Show that the second solution y2 that we found in part (b) cannot be expressed as a Frobenius series.