Special angle introduction:
Generally refers to the angle of 0, 30, 45, 60, 90, 120, 135, 150, 180, 270, 360. These angles are often used, so remember their corresponding trigonometric function values, including sine value, cosine value, tangent value, cotangent value and so on.
When it comes to special angles, we can soon think of angles of 30, 45, 60 and 90. In fact, the above angles can be called special angles because of their special trigonometric functions, such as all ten. Why do we call 60 a special angle while 50 is not? The reason is simple, COS60 = 1.
Special angles in the coordinate system:
When we first touch the plane rectangular coordinate system, we know the bisectors of the first and third quadrants and the bisectors of the second and fourth quadrants, that is, the straight line y=x and the straight line y =-x. In the linear function, we know that if two straight lines are parallel, then k is equal. Based on the above two points, it can be concluded that the angle between the straight line y=x+m or y=-x+m and the X axis is 45.
Introduction of angular coordinate system;
Angle coordinate system is a three-dimensional coordinate system, which is used to determine the positions of points, lines, surfaces and bodies in three-dimensional space. It takes coordinate origin and coordinate unit point as reference points, and consists of azimuth 1, azimuth 2 and rotation angle.
In mathematics, the angular coordinate system (English) is a three-dimensional orthogonal coordinate system that uses angles to represent the position of a point P in three-dimensional space. It is determined by the angle φ 1 between the straight line from coordinate origin O to point P and Z axis, φ2 between the straight line from point A to point P and θ 1 between opa plane and OXZ plane, that is, the coordinates of point P are (φ 1, φ2, θ 1).