Codes for graphing tangent/cotangent functions

I have created a review activity where students drag points to make asymptotes and graphs. When all of the points are at the correct coordinates, the graphs appear.

Problem is that the graph is not appearing. This is y=tan2x The points are correct, I am counting by values that should give exact y-values for the equation.

I have defined my tangent function as

The function stays undefined at correct6 and correct4 even when I drag my points to exactly correct coordinates.

Is there a different way to define the function?

I figured something out.