Page 316 - Schaum's Outline of Differential Equations
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CHAP.  30]                    GAMMA AND BESSEL   FUNCTIONS                           299



               Thus,
               and,  in  general,





                                 2
                                    2
               The indicial equation  is X  -  p  = 0, which has the roots 'k\=p  and X 2 = —p (p  nonnegative).
               Substituting  'k = p  into  (_/)  and  (2) and simplifying,  we find  that a l = 0 and




               Hence,  0 = aj = a 3 = a s = a 7 = • • •  and










               and,  in  general,






               Thus,






                  It is customary  to choose the arbitrary constant a 0 as  a 0 =  .  Then  bringing a Qx p  inside the  brackets
               and summation in  (3),  combining, and finally  using Problem  30.4,  we  obtain









         30.10.  Find the general solution to Bessel's equation of order zero.
                                    2
                                            2
                  For p = 0, the equation is x y" + xy' + x y = 0, which was solved in Chapter 28. By (4) of Problem 28.10, one solution is




               Changing  n to k, using Problem  30.6,  and letting  = 1 as indicated  in Problem  30.9,  it follows that
               y\(x)  = JQ(X).  A  second  solution  is  [see  (_/)  of Problem  28.11, with a 0 again  chosen  to be 1]
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