How to add a single point to a plot?

[singlets]

Hello,

I'm trying to add a single point to the plot of a function with the goal of highlighting a critical point. The docs suggest this is possible (but maybe I misunderstand them): "The figure can contain an arbitrary number of plots of sympy expressions, lists of coordinates of points, etc." http://docs.sympy.org/dev/modules/plotting.html

And "plot(list_x, list_y)" from https://github.com/sympy/sympy/wiki/Plotting-capabilities.

I don't seem to have any luck, getting errors when passing a list or tuple to plot(). Is it possible to add a single point to a plot of expression(s)?

My kludgy workaround is to lambdify the sympy function and use matplotlib, but I suspect I'm missing a better way.

Thanks,
Steve