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Differential Equations & Partial Differential Equations

                                +
                   (d) e  / x y  =  x c                                  (b)  x 2 ( 2x e − y 2 )  =  c
                                                                                    +
            7.     The differential equation                                            2
                                                                                   +
                   2ydx −   (3y −  2x )dy =                              (c)  x ( 2x e −  y  )  =  c
                                            0

                   (a) exact and homogeneous but not                     (d)  x ( 2x e − y 2 )  =  c
                                                                                   −
                   linear
                                                                                               [JAM CA 2006]
                   (b) homogeneous and linear but not

                   exact                                          10.    The solution of the initial value
                                                                         problem  xy −  1  y =  0  with
                   (c) exact and linear but not                             1
                                                                                      y
                   homogeneous                                           xy −   y =  0 ( ) 1 = 1 is

                                                                                     x
                                                                             y
                   (d) exact, homogeneous and linear                     (a)  ( ) x =
                                         [JAM CA 2006]                               1
                                                                             y
                                                                         (b)  ( ) x =
            8.     The general solution of the                                       x
                                                                             y x =
                   differential equation                                 (c)  ( ) 2x −    1
                   (x + −     ) 3 dx − (2x +  2y +  ) 1 dy =
                                                         0
                         y
                   is                                                    (d)  ( ) x =   1    [JAM CA 2007]
                                                                             y
                                                                                     2x −  1
                                                    k
                   (a) ln 3x + 3y −  2 + 3x +  6y =
                                                                  11.    The solution of the differential
                                                                         equation
                                                    k
                   (b) ln 3x + 3y −  2 − 3x − 6y =                           x sin  y  −  y cos  y     dx x cos dy =  0
                                                                                                          y
                                                                                                  +
                                                      k
                   (c) 7ln 3x +  3y −  2 + 3x + 6y =                           x         x          x
                                                                                                 y
                                                                                                        0
                                                                          with initial condition  ( ) 0 =  is
                                                      k
                   (d) 7ln 3x +  3y − 2 −  3x +  6y =                              y
                                                                                                          
                                                                             x
                                                                         (a)  sin     = 1      (b)  y =   n x
                                         [JAM CA 2006]                             x
            9.     The general solution of the                                         y
                   differential equation                                 (c)  y =  x  sin  x     (d)  x =  y
                   ( 6x −  e −  y 2 ) dx +  2xye −  y 2 dy =  0 is
                       2
                                                                                               [JAM CA 2008]



                                                                  12.    The differential equation
                                                                             2
                              −
                   (a)  x 2 ( 2x e − y 2 ) =  c                          (2x +   by 2 ) dx cxydy+  =  0  is made
                                                                         exact by multiplying the integrating





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