1 - 2*sin(x) > cos(x)
(pi - atan(4/3), 2*pi)
x in Interval.open(pi - atan(4/3), 2*pi)
And(x < 2*pi, pi - atan(4/3) < x)
(x < 2*pi)∧(pi - atan(4/3) < x)