2 3 2 3 sin(x) + 3/2 > - sin (x) + - - cos (x) + - 2 2
sin(x) + 3/2 > 3/2 - sin(x)^2 - cos(x)^2 + 3/2
/pi 5*pi\ And|-- < x, x < ----| \6 6 /
(pi/6 < x)∧(x < 5*pi/6)
pi 5*pi (--, ----) 6 6
x in Interval.open(pi/6, 5*pi/6)