3sinx+2(1-sin²x)≥03sinx+2-2sin²x≥0-2sin²x+3sinx+2≥02sin²x-3sinx-2≤0y=sinx2y²-3y-2≤02y²-3y-2=0D=9+16=25y₁=(3-5)/4=-2/4=-1/2y₂=(3+5)/4=2 + - +--------- -1/2 ----------- 2 ---------------- \\\\\\\\\\\\\\\\y∈[-1/2; 2]-1/2≤sinx≤2sinx≥-1/2x∈[-π/6+2πk; 7π/6+2πk], k∈zsinx≤2sinx≤1x - любое числоОтвет: [-π/6+2πk; 7π/6+2πk], k∈Z.