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176   5. Further Determinant Theory

                                     yA 1               vy
                              = D n       ,    A 1 = u =
                                      v                  y
                              = D n+1 (y).

          Hence,
                                       v n+1 D n+1 (y)
                                A n+1 =            ,
                                             y

          which is equivalent to (b).
                                                                     (α)
            The Rodrigues formula for the generalized Laguerre polynomial L n (x)
          is
                                                x
                                       x D (e −x n+α )
                                        n
                                           n
                               (α)
                              L  (x)=                 .             (5.1.16)
                                         n! e −x n+α
                                              x
                               n
          Hence, choosing
                                    v = x,
                                    y = e −x n+α ,
                                           x
          so that
                                   u = x − n − α,                   (5.1.17)

          formula (b) becomes
                   1
           (α)
          L  (x)=    ×                                              (5.1.18)
                   n!
           n
                          1

            n + α − x
                     n + α − x − 1     2

              −x

                                  n + α − x − 2  3

                                                                          .
                         −x

                                      ···     ···  ···   ···

                                                                  n − 1

                                                      2+ α − x

                                                         −x     1+ α − x  n

          Exercises
          Prove that
                          n + α − x  n + α      n + α     n + α    ···

                             1      n + α − x   n + α     n + α

                                                                   ···
          1. L (α) (x)=  1             2      n + α − x   n + α
                                                                   ···
              n
                                                  3
                      n!
                                                         n + α − x ···
                                                       ................

                                                                      n
                                                                 (Pandres).
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