If you reach the edge of the screen, remember that the slope line actually points in two opposite directions, so now drag back over the trace you've already left and continue in the other direction. Keep going until you either reach the other edge of the screen or until your trace returns to a location near the starting position. You can let go of the mouse now, but be careful not to click anywhere or the trace will disappear. The on-screen trace represents an approximation of the differential equation's particular solution which includes your initial starting point P . Now move point P someplace in the sketch away from the current trace and let go.
P now represents a point on some other particular solution to the differential equation.
Repeat Steps 1-4 to trace the new solution. Then repeat a third time for a third starting place.