By default the plot function has only 200 points:
sage.plot.plot.plot(funcs, exclude=None, fillalpha=0.5, fillcolor='automatic', detect_poles=False, plot_points=200, thickness=1, adaptive_tolerance=0.01, rgbcolor=(0, 0, 1), adaptive_recursion=5, aspect_ratio='automatic', alpha=1, legend_label=None, fill=False, *args, **kwds)
But this look awful when plotting for example $f(x) = \frac{\sin x }{x}$. Since my machine is quite fast, I'd like to set the default to 50000 points.
Is this possible?
