sin(2*x) - sin(x) - cos(x) - 1 < 0
-sin(x) + sin(2*x) - cos(x) - 1 < 0
3*pi [0, pi) U (----, 2*pi] 2
x in Union(Interval.Ropen(0, pi), Interval.Lopen(3*pi/2, 2*pi))
/ / 3*pi \\ Or|And(0 <= x, x < pi), And|x <= 2*pi, ---- < x|| \ \ 2 //
((0 <= x)∧(x < pi))∨((x <= 2*pi)∧(3*pi/2 < x))