(x + y) dy + (x – y) dx = 0; y = 1 when x = 1
12 x2 dy + (xy + y2) dx = 0; y = 1 when x = 1
13 sin2
0;
4
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
y
x
y dx
x dy
y
x
 when x = 1
14 cosec
0
dy
y
y
dx
x
⎛x
⎞
−
+
=
⎜
⎟
⎝
⎠
;  y = 0 when x = 1
15