Page 118 - Engineering Mathematics Workbook_Final
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Differential Equations & Partial Differential Equations

            206.  The solution of the differential                209.  The solution of
                   equation                                               dy  =     +  tan  
                                                                                 y
                                                                                             y
                                                                                
                                                                                            
                                                                               
                                                                                             
                                                                          dx              x   is
                                                                                 x
                                                                                
                                                                                            
                            2
                                       −
                        −
                                           2
                                                  0
                    y  1 x dy +    x  1 y dx =  is
                                                                                    y   
                          −
                   (a)  1 x =  2  c                                      (a) sin      x      =  xc
                                                                                   y 
                   (b)  1 y−  2  =  c                                    (b) tan           =  xc
                                                                                   x 
                           −
                              2
                                      −
                                         2
                   (c)   1 x +      1 y =                                            y 
                                             c
                                                                         (c) cosec           =  xc
                                     +
                              2
                   (d)  1 x +      1 y =                                               x 
                                         2
                          +
                                             c
                                                                         (d) cot      y      =  xc
                                        [ESE-2017 (EE)]                            x 
            207.  The figure shows the plot of y as a             210.  Solve the differential equation,
                   function of x. The function shown is                     2  dy    3    3
                   the solution of the differential                      xy   dx  =  x +  y
                   equation (assuming all initial
                   conditions to be zero) is                                                [GATE-1994-ME]
                         2
                       d y                   dy                   211.  A curve passes through the point (x =
                   (a)      = 1          (b)    = +  x                   1, y = 0) and satisfies the differential
                       dx 2                  dx
                                                                                           2
                       dy                    dy                                    dy  =  x +  y 2  +  y
                   (c)     = −  x        (d)    =  x                     equation   dx      2y      x  . The
                       dx                    dx
                                                                         equation that describes the curve is
                               [GATE-2014 (IN-SET 1)]
                                                                                   y 2   
                                                                               
              HOMOGENEOUS DIFFERENTIAL                                   (a) ln 1+    2     =  x − 1
                                                                               
                            EQUATION                                                x  

                                    dy                                       1       y 2   
            208.  The solution of       =  sin (x +  ) y  is             (b)  ln 1+         =  x − 1
                                                                                 
                                    dx                                       2       x 2   
                           (
                                  ) sec x +
                                                    x c
                   (a) tan x +  y −      (      ) y = +                             y 
                                                                               
                                                                         (c) ln 1+   x        =  x − 1
                                                                               
                                                   2
                          (
                   (b) sec x +  y ) tan x−  ( +  ) y =  x  + c                        
                                                  2
                                                                             1        y   
                           (
                                                                                  
                                                      +
                   (c) tan x +  y ) cos x−  ( +  ) y =  x c              (d)  ln 1+    x        =  x − 1
                                                                             2
                                                                                  
                           (
                                                      +
                   (d) tan x +  y ) cot x−  ( +  ) y =  x c
                                                                                            [GATE 2018 (EC)]

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