Question
Question: The general solution of the differential equation (*x* + *y*)*dx* + *xdy* = 0 is...
The general solution of the differential equation (x + y)dx + xdy = 0 is
A
x2+y2=c
B
2x2−y2=c
C
x2+2xy=c
D
y2+2xy=c
Answer
x2+2xy=c
Explanation
Solution
We have xdx + (ydx + xdy) = 0 ⇒ xdx + d(xy) = 0
Integrating, 2x2+xy=2c
∴ x2+2xy=c