See the attachment
on the left is F = i +2 j since the components are constant all vectors
should point in the same direction
On the right is what F = x i + 2y j would look like
By the way how did your test go ?
draw the vector field for
f(x,y)= (1,2) with starting points (0,0) and (3,1)
should i change (1,2) to like (x,2y) or something? otherwise all of the points would be pointing to the point (1,2) and this does not match the graph in the back of the book