3 3 3 (x + 1) + (x - 2) >= 2*(x - 1/2)
(x - 2)^3 + (x + 1)^3 >= 2*(x - 1/2)^3
[1/2, oo)
x in Interval(1/2, oo)
And(1/2 <= x, x < oo)
(1/2 <= x)∧(x < oo)