The cosine function is one of the more common circular functions.[br][br]The domain of the cosine is (-inf, inf). The base range is (-1, 1).

The red dashed line is the base cosine function.[br]One period is always highlighted.[br][br]The blue line is the cosine in general form.[br][br]This applet can be used by teachers in a demonstration mode in the classroom or teachers can have students load it on their own computers with a worksheet to be complete for a grade.