设集合A={x┃x*x-(2a+3)x+a*a+3a≤0},B={x┃x≤-1或x>5},分别求出下列条件实数a的值 (1)A∩B=空集 (2)A含于B
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![设集合A={x┃x*x-(2a+3)x+a*a+3a≤0},B={x┃x≤-1或x>5},分别求出下列条件实数a的值 (1)A∩B=空集 (2)A含于B](/uploads/image/z/9291282-42-2.jpg?t=%E8%AE%BE%E9%9B%86%E5%90%88A%3D%7Bx%E2%94%83x%2Ax-%282a%2B3%29x%2Ba%2Aa%2B3a%E2%89%A40%7D%2CB%3D%7Bx%E2%94%83x%E2%89%A4-1%E6%88%96x%EF%BC%9E5%7D%2C%E5%88%86%E5%88%AB%E6%B1%82%E5%87%BA%E4%B8%8B%E5%88%97%E6%9D%A1%E4%BB%B6%E5%AE%9E%E6%95%B0a%E7%9A%84%E5%80%BC+%281%29A%E2%88%A9B%3D%E7%A9%BA%E9%9B%86+%282%29A%E5%90%AB%E4%BA%8EB)
设集合A={x┃x*x-(2a+3)x+a*a+3a≤0},B={x┃x≤-1或x>5},分别求出下列条件实数a的值 (1)A∩B=空集 (2)A含于B
设集合A={x┃x*x-(2a+3)x+a*a+3a≤0},B={x┃x≤-1或x>5},分别求出下列条件实数a的值 (1)A∩B=空集 (2)A含于B
设集合A={x┃x*x-(2a+3)x+a*a+3a≤0},B={x┃x≤-1或x>5},分别求出下列条件实数a的值 (1)A∩B=空集 (2)A含于B
A={x┃x*x-(2a+3)x+a*a+3a≤0}
={x┃(x-a)(x-a-3)≤0}
={x┃a≤x≤a+3}
B={x┃x≤-1或x>5}
(1)A∩B=空集
a+3≤5且-15
集合A={x┃x*x-(2a+3)x+a*a+3a≤0}
=={x┃a≤x≤a+3}
B={x┃x≤-1或x>5},
1、A∩B=空集
a>-1 且 a+3≤5
解得 -12、A含于B
a>5 或 a+3≤-1
解得 a>5 或 a≤-4