tan(pi) tan(2*x) <= ------- 3
tan(2*x) <= tan(pi)/3
/ /pi pi\ \ Or|And|-- < x, x < --|, x = 0| \ \4 2 / /
(x = 0))∨((pi/4 < x)∧(x < pi/2)
pi pi {0} U (--, --) 4 2
x in Union(FiniteSet(0), Interval.open(pi/4, pi/2))