In the plane rectangular coordinate system, the quadrant takes the origin as the center and the X and Y axes as the dividing lines. The upper right is called the first quadrant, the upper left is called the second quadrant, the lower left is called the third quadrant, and the lower right is called the fourth quadrant. The points on the coordinate axis do not belong to any quadrant.

Mainly used in trigonometry and complex Argentine coordinate system (complex plane).

Nature:

1, points in the first quadrant:

2. Points in the second quadrant:

3. Points in the third quadrant:

4. Points in the fourth quadrant:

Extended data:

corner

1, the first quadrant angle:

2. The second quadrant angle:

3. The third quadrant angle:

4. The fourth quadrant angle: