How to use this applet:

Notes on the maths used in the applet:

Trigonometric functions are periodic functions, that means that they are of the form
        f(x + T) = f(x),  T = const.
The smallest number which satisfies this relation is called period.
 
The general sinus-function is of the form
        f(x) = a * sin(b * x)
a is called amplitude, that is the biggest distance from the x-axis.
b is called frequency.
The period is
        T  = 2pi / b

The sinus-function cuts the a-axis at
        Bn = (npi / b, 0),  n is a natural number.
The extreme values are at
        Cn = ((k + 1/2)pi / b, (-1)^n * a),  n is a natural number.
 
The general cosinus-function is of the form
        f(x) = a * cos(b * x)
this is equivalent to
        f(x) = a * sin(b * x + pi/2)
the general sinus-function with phase-shift of pi / 2.
 
The general tangens-function is of the form
        f(x) = a * tan(b * x)
The period is
        T = pi / b.
 
The function increases monotonous for x in the interval ]-pi / 2b, pi / 2b[ between
-INFINITE to INFINITE.