Quadrant (plane geometry)

A quadrant (Latin quadrans, district ') is a limited by two coordinate axes section of a plane, the points on the bounding axes usually belong to any quadrant.

According to the usual conventions of the first quadrant is drawn on the top right. In a Cartesian coordinate system of the four quadrants in the counterclockwise direction with I, II, III, IV, or 1, 2, 3, 4 are indicated. A point in the first quadrant then each positive coordinates.

However, there are also other organizations use.

Reference to trigonometry

And their 360 ° - periods - - In trigonometry, the signs of the trigonometric functions sine, cosine, tangent and cotangent depend on the angle extends into which quadrant:

Each of the trigonometric functions of angles has the same sign in two quadrants. Therefore, the archetype of the value of a trigonometric function, eg of the sinus, ambiguous. Some can be made of an angle α in the third or fourth quadrant, that is π < α <2 · π or 180 ° < α resulting < 360 °.

A quadrant table - or a corresponding query in a PC program - is always necessary in geodesy and navigation to coordinates of two points from the direction ( azimuth, the course) to be calculated.