The two coordinates ρ and θ in polar coordinate system can be converted from x=ρcosθ and y=ρsinθ to coordinate values in rectangular coordinate system. Calculate the coordinates in polar coordinates from the X and Y coordinates in rectangular coordinate system: θ=arctan(y/x)(x≠0).

Polar coordinates:

An important feature of the polar coordinate system is that any point in the plane rectangular coordinate system can have infinite expressions in the polar coordinate system. Generally speaking, the point (r, θ) can be arbitrarily expressed as (r, θ 2kπ) or (? R, θ (2k+ 1) π), where k is an arbitrary integer. If the r coordinate of a point is 0, then no matter what value θ takes, the position of the point falls on the pole.

The angle in polar coordinate system is usually expressed by angle or radian, and the formula 2 π rad = 360. Which method to use is basically determined according to the usage. In navigation, angle is often used to measure, while in some fields of physics, the ratio of radius to circumference is widely used to calculate, so radian is more inclined to be used in physics.

1. In mathematics, the polar coordinate system is a two-dimensional coordinate system. Any position in the coordinate system can be expressed by the included angle and the distance from the origin to the pole. Polar coordinate system has a wide range of applications, including mathematics, physics, engineering, navigation, aviation and robotics.

2. Polar coordinate system is particularly useful when the relationship between two points can be easily expressed by included angle and distance; In the plane rectangular coordinate system, such a relationship can only be expressed by trigonometric functions. For many types of curves, polar coordinate equation is the simplest expression, and even for some curves, only polar coordinate equation can be expressed.