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Differential and Integral Equation




                    Notes
                                               v 3  2       dx
                                   or             2     dv
                                           ( v v  1)(v  v  1)  x
                                              2   1    2v  1
                                   or                  2      dv  log cx
                                              v  v  1  v  v  1

                                             (v  1)(v 2  v  1)
                                   or     log       2       logcx
                                                   v

                                          (y x y 2  xy x 2
                                               )
                                   or                      cx
                                                 3 y 2
                                                x  2
                                                  x
                                            2 2
                                           x y
                                   or      3   3  . k
                                          x   y
                                           dx /x    dy /y      dz
                                   Also    3    3    3  3           .
                                          y   2x   2y  x   9z x 3  y  3

                                          dx /x dy /y  dz
                                                         .
                                               1       3z
                                          3 log x + 3 log y =   log cz
                                           3 3
                                   or     x y  = 1/cz.
                                              1    x   y
                                          z   3 3   2   2  .
                                             x y   y   x

                                                        (y z )p  (z x )q  x y
                                          Example 7: Solve:                .
                                                          yz      zx    xy
                                   Solution:

                                          (xy   zx) p + (yz   yx) q = zx   zy.

                                            dx    dy      dz
                                                              .
                                          y zx   yz yx  zx zy
                                          dx + dy + dz = 0
                                   or     x + y + z = c .
                                                   1
                                   Also   yz dx + zx dy + xy dz = 0.

                                          dx  dy  dz
                                   or                0.
                                           x   y  z
                                          log x + log y + log z = log c .
                                                                2
                                          xyz = c .
                                               2





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