first inequality gives (2sinx−1)(sinx+2)>0 (sinx−12)>0 Π6<x<5Π6 second inequality gives (x+1)(x−2)<0 −1<x<2 common part is Π6<x<2
Let 2sin2x+3sinx−2>0 and x2−x−2<0 (x is measured in radians). Then x lies in the interval