I tried like in tutorial
sage: t = var('t')
sage: p1 = plot(cos(2*t) + 2*cos(t), (t,0, 2*pi), rgbcolor=hue(0.3))
sage: p2 = plot(4*cos(t) - cos(2*t), (t,0, 2*pi), rgbcolor=hue(0.6))
sage: show(p1 + p2)
and I can see a beautiful bicolour image of the 2 curves
But then impossible to find the touch combination (I tried a lot , q, Q, Ctrl D, exit, quit, escape.....) to exit the graph an return to sage command line
