题目
设向量a=(1,x),b=(2,1-x),若a·b＜0，则实数x的取值范围是_____________.
答案：(-∞,-1)∪(2,+∞)解析:∵a·b＜0,∴2-x(1-x)＜0,即x2-x+2＜0,解得x＜-1或x＞2.
数学 试题推荐
最近更新
- 依次填入下面一段文字横线处的语句，衔接最
- 下列各句中，划线的成语使用正确的一项是(2
- Shelly had worked hard for her biology examination so that s
- 酒精温度计中的液柱随温度的变化而升降，这
- 近两年，肇庆的空气质量显著下降，其原因最
- PCNA是一类只存在于增殖细胞中的阶段性合成
- 相同温度下，在体积相等的三个恒容密闭容器
- 阅读下文，完成1—5题。 沛公已出，项王使都
- It is________that so many young athletes are coming into th
- The carbon content of steel largely determines its usefulne
- There was less food for birds and also for the Prairie dog,
- The girl is very ________ to tell her parents about the tru
- 若不等式组有解，则m的取值范围是______．
- 根据细胞器的功能推测，下列叙述错误的是（
- In order to improve relationship with others, you need to be
- 下图为新中国人口自然变动图，根据图上曲线
- — What’s this in English? — ________. A. It’s bag
- You should ask Bob ________ his own clothes. He is ten year
- 3．依次填入下面一段文字横线处的句子，衔
- 以下表述正确的是( )A．抗原入侵机体时，免
