Graph of tangent is incorrect

[hackerb9]

The graph of $\tan(x)$ is incorrect and changes wildly as the graph is zoomed. This may be related to #218 as it appears to be (possibly) sampling at too low of a frequency and then linearly interpolating.

There exist algorithms for ensuring the correct sampling of possibly asymptotic functions, but I believe a simple solution would be to simply take many more measurements than is currently done.
(Perhaps a hundred times?)