The tangent function is the reciprocal of the cotangent function.[br][br]One of the distinct features of the tangent is the asymptotes which you can switch off with the check box.

The red dashed line is the base tangent function.[br]One period is always highlighted.[br][br]The blue line is the tangent 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.