Copia de The unit circle and trigonometric functions
The following applet is devoted to show how the (circular) trigonometric functions graphs can be traced from a unit circle centered at the origin. In every case, the fisrt coordinate equals the distance between the origin and the circle center, which is equal to the length of the arc from the horizontal axis to the intersection point between a radius and the circumference. On the other hand, the second coordinate corresponds to the length of the highligthed segment together with its orientation. For sine, cosine, secant and cosecant, only the fundamental period is shown, and for tangent and cotangent a period and a half are shown.