- In Problems 25-30, x = 0 is a regular singular point of the given differential equation. Show that the indicial roots of the singularity differ by an integer. Use the method of Frobenius to obtain at least one series solution about x = 0. Use (21) where necessary and a CAS, if instructed, to find a second solution. Form the general solution on the interval (0, ∞). 25. xy" +2y' - xy = 0 26. x²y" + xy' + (x² - y = 0 27. xy" - xy' + y = 0