Sin(x) and Cos(x) from the Unit Circle (3D)

This example demonstrates the sine and cosine functions from the unit circle in a 3D view. ① It illustrates how the sine and cosine values are defined by the projections of a point P on the unit circle onto the x-axis and y-axis. ② The core mathematical concepts involved include angles, the unit circle, sine function, cosine function, trigonometric functions, and coordinate geometry. ③ The construction uses GeoGebra commands such as Circle, Vector, Segment, CurveCartesian, and Angle, along with objects like UC (unit circle), θ (angle), r (radius), vseg (vertical segment), hseg (horizontal segment), sincurve (sine curve), coscurve (cosine curve), sinvec (sine vector), cosvec (cosine vector), ang (angle), and P. ④ It is suitable for high school mathematics students to learn and understand the relationship between trigonometric functions and the unit circle, and can also be used in calculus and coordinate geometry teaching.