The formula of the distance between two coordinate points is |AB|=√[(x 1-x2)? +(y 1-y2)？ ]。 Coordinates, mathematical nouns. Refers to the spherical coordinate system established on the celestial sphere to determine the position of a point on the celestial sphere. The basic plane with two basic elements is determined by the selected great circle on the celestial sphere. The great circle is called the base circle, and one of the two geometric poles of the base circle is the pole of the spherical coordinate system. The principal point, also known as the origin, is determined by the intersection of the great circle of the selected pole in the celestial sphere and the base circle.

Coordinate function

In order to determine the position of stars in the sky, ancient astronomers naturally used a method similar to coordinates, that is, dividing the sky into grids and determining the position of stars according to the grid position. The ancient Greek astronomer Hipparchus, about 190 to 125, was also translated as Ibagu.

This is because in the process of translating Greek, Latin and Chinese, latitude and longitude are used to mark the position of the midpoint in the sky, just like drawing a grid on the sky, which can mark and find all kinds of stars quickly.