题目
If -2 < t < 0 and 0 < v < 2, then which of the following must be true?
I. tv - v < 0
II. t2 – v2 > 0
III. (t–v)2< 4
解析
如果\(-2 < t <0\)且\(0 < v <2\),那么以下哪项一定正确?
I. \(tv - v<0\)
II. \(t^{2}-v^{2}>0\)
III. \((t - v)^{2}<4\)
**对于I选项**
已知\(-2 < t<0\)且\(0 < v <2\),将\(tv - v\)提取公因式\(v\)得到\(v(t - 1)\)。
因为\(0 < v<2\),且\(-2