If P is point which is element of A={(x,y)| x.y>0 and x,y∈R}, P lies in first quadrant or third quadrant
If P is point which is element of B={(x,y)| x.y<0 and x,y∈R}, P lies in second quadrant or forth quadrant
ıf abcissa of point is zero, point lies on y axis
If ordinate of point is zero, point lies on x axis
