This demonstration shows how the graphs of the 6 trigonometric functions are related to the Unit Circle. The point A is animated around the circle and each function is plotted as a point. For example, the sine curve is plotted by tracing the point [math](\alpha, sin(\alpha))[/math] where [math]\alpha[/math] is an angle between 0 and [math]2\pi[/math]. [br][br]The trace changes from black to red when the function passes from being positive to negative.[br][br][math]\tan\left(\alpha\right)=\frac{\sin\left(\alpha\right)}{\cos\left(\alpha\right)}[/math] is the slope of the line segment shown, which means [math]\cot\left(\alpha\right)[/math] is the reciprocal of the tangent.