Dynamic Demonstration of Trigonometric Induction Formula I (Periodicity)

This applet dynamically demonstrates Trigonometric Induction Formula I, illustrating the periodic relationships of trigonometric functions (e.g., sin(α+2kπ)=sinα, cos(α+2kπ)=cosα, tan(α+2kπ)=tanα). By constructing the terminal sides of angle α and α+2kπ on the unit circle, it visually reveals the coordinate patterns of the corresponding points, intuitively explaining the periodic nature of sine, c