Ответ:
1) x∈[-2,0} ∪ {2,4]
2)x∈{-2/3, 2 - √6] ∪ [2 + √6, + ∞}
Пошаговое объяснение:
1)log2(x²-2x)≤3, x ∈ {-∞, 0} ∪ {2 + ∞}
x²2-2x≤2^3
x²2-2x≤8
x²-2x-8≤0
x²+2x-4x-8≤0
x(x+2)-4x-8≤0
x(x+2)(x-4)≤0
x+2≤0
⎨ x-4≥0
x+2≥0
⎨ x-4≤0
x≤-2
x≥-2
⎨ x≤4
x ∈ [- 2 , 4], x ∈ {-∞ , 0} ∪ {2 , +∞}
x∈[- 2 , 0} ∪ {2 , 4]
2) log3(x²-x)≥log3(3x+2), x∈{-2/3 , 0} ∪ {1, +∞}
x²-x≥3x+2
x²-x-3x-2≥0
x²-4x-2≥0
x²-4x-2=0
x1=2+√6
x2=2-√6
(x-(2+√6))*(x-(2-√6))≥0
(x-2-√6)*(x-(2-√6))≥0
x-2-√6≥0
⎨x-2+√6≥0
x-2-√6≤0
⎨x-2+√6≤0
x≥2+√6
x∈[2+√6 , +∞}
x≤2+√6
⎨x≤2-√6 ⎬
x∈{-∞, 2-√6]∪[2+√6 , +∞} , x∈{-2/3 , 0}∪{1, +∞}
x∈{-2/3, 2 - √6] ∪ [2 + √6, + ∞}
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Answers & Comments
Ответ:
1) x∈[-2,0} ∪ {2,4]
2)x∈{-2/3, 2 - √6] ∪ [2 + √6, + ∞}
Пошаговое объяснение:
1)log2(x²-2x)≤3, x ∈ {-∞, 0} ∪ {2 + ∞}
x²2-2x≤2^3
x²2-2x≤8
x²-2x-8≤0
x²+2x-4x-8≤0
x(x+2)-4x-8≤0
x(x+2)(x-4)≤0
x+2≤0
⎨ x-4≥0
x+2≥0
⎨ x-4≤0
x≤-2
⎨ x-4≥0
x≥-2
⎨ x-4≤0
x≥-2
⎨ x≤4
x ∈ [- 2 , 4], x ∈ {-∞ , 0} ∪ {2 , +∞}
x∈[- 2 , 0} ∪ {2 , 4]
2) log3(x²-x)≥log3(3x+2), x∈{-2/3 , 0} ∪ {1, +∞}
x²-x≥3x+2
x²-x-3x-2≥0
x²-4x-2≥0
x²-4x-2=0
x1=2+√6
x2=2-√6
(x-(2+√6))*(x-(2-√6))≥0
(x-2-√6)*(x-(2-√6))≥0
x-2-√6≥0
⎨x-2+√6≥0
x-2-√6≤0
⎨x-2+√6≤0
x≥2+√6
⎨x-2+√6≥0
x-2-√6≤0
⎨x-2+√6≤0
x∈[2+√6 , +∞}
x≤2+√6
⎨x≤2-√6 ⎬
x∈{-∞, 2-√6]∪[2+√6 , +∞} , x∈{-2/3 , 0}∪{1, +∞}
x∈{-2/3, 2 - √6] ∪ [2 + √6, + ∞}