若ABCD是正方形,E是CD的中点,且 ,则 =( )A.![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001806-54316.png) | B.![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001806-67673.png) | C.![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001806-99036.png) | D.![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001806-85473.png) |
答案
B |
举一反三
若非零向量 满足 ,则( )A.![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001756-74748.png) | B.![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001757-24374.png) | C.![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001757-21740.png) | D.|![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104001757-50266.png) | 下列等式中,正确的个数是( ) ①+=+; ②-=-; ③-=-; ④-(-)=; ⑤+(-)=0. | 下列四式中不能化简为的是( )A.(+)+ | B.(+)+(+) | C.(+)- | D.(-)+ |
| 在△ABC中,点M满足++=,若 ++m=,则实数m的值是( ) | 已知向量,满足:对任意λ∈R,恒有|-λ(-)|≥,则( )A.||=|-| | B.||=|| | C.||=|+| | D.||=2|| |
|
最新试题
热门考点
|
|