21
The Mathematica code
f := #1 + Sin[2 #1] &;
inflectionPoints = Table[{x, f[x]}, {x, -Pi, Pi, Pi/2}];
stationaryPoints = Union[
Table[{x, f[x]}, {x, -2 Pi/3, Pi/3, Pi}],
Table[{x, f[x]}, {x, -Pi/3, 2 Pi/3, Pi}]];
Show[Plot[f[x], {x, -Pi - 1, Pi + 1}],
ListPlot[{stationaryPoints,...