
In the above diagram, X and Y axes divided the plane into four regions and these regions are called Quadrants and they are numbered Q_{1}, Q_{2}, Q_{3} and Q_{4}, in the anti clock wise direction the first quadrant is denoted as Q_{1}, the second quadrant is denoted as Q_{2}, the third quadrant as Q_{3} and the fourth quadrant as Q_{4}. The right hand side towards east form the Yaxis is considered as positive direction. The left hand side towards west from the Yaxis is considered as negative directions. The upward direction towards north from Xaxis is positive direction and the downward side towards the south is negative direction.
In the first quadrant Q_{1} the coordinates x and y are (+,+). That is a positive real number and a positive real number. 