(896, #15) If you have a CAS that plots vector fields

(896, #15) If you have a CAS that plots vector fields use it to plot
F(x, y) = .
Explain the appearance by finding the set of points (x, y) such that F(x, y) = 0.
Solution: We can construct a sketch for the vector field using Maple's fieldplot( ) command:

In order for F( x, y )= 0 to be valid, we must have and
For this to occur, the first equation must have y = 0 or y = 2x, and the second must have x = 0 and y = 2x. Therefore, along the line y = 2x the statement F( x, y ) = 0 is valid.
The blurry image along the line y = 2 x in the graphic represents the fact that F (x, y) = 0 along this line.
Maple code