sqrt(3)sinx + cosx =< 1
sqrt(3)sinx/2 + cosx/2 =< 1/2
cos(π/6)sinx + sin(π/6)cosx =< 1/2
sin(x + π/6) =< 1/2
-7π/6 + 2πn =< x + π/6 =< π/6 + 2πn
-4π/3 + 2πn =< x =< 2πn ; n € Z
x € [-4π/3 + 2πn ; 2πn] ; n € Z
