已知集合A={x |x^2-x-12<0},B={x |x^2<a^2,a>0}若A}B，求實數(shù)a的取值范圍
熱心網(wǎng)友
集合A={x|x^2-x-12＜0} →(x+3)(x-4)＜0 → A={x|-3＜x＜4}集合B={x|x^2＜a^2,a＞0} → B={x|-a＜x＜a}∵A包含B且a＞0∴0＜a≤3
已知集合A={x |x^2-x-12<0},B={x |x^2<a^2,a>0}若A}B，求實數(shù)a的取值范圍
集合A={x|x^2-x-12＜0} →(x+3)(x-4)＜0 → A={x|-3＜x＜4}集合B={x|x^2＜a^2,a＞0} → B={x|-a＜x＜a}∵A包含B且a＞0∴0＜a≤3