四川单招数学试题
2.请将答案正确填写在答题区域,注意书写工整。一.选择题(每题5分,共50分)1.已知全集U=R,A= \{ x \mid x \le 0 \} ,B= \{ x \mid x \ge 1 \} ,则集合{,(AUB)等于()A.\{ x \mid x \ge 0 \}B.\{ x \mid x \le 1 \}C.\{ x \mid 0 \le x \le 1 \}D.\{ x \mid 0<x<1 \}2.不等式\frac {x-1}{x-2} \ge 0的解集为()A.[1,2]B.(- \infty ,1] \cup [2,+\infty)C.[1,2)D.(- \infty ,1] \cup(2,+\infty)3.设D为\triangle ABC所在平面内一点,\overrightarrow {BD}=3 \overrightarrow {CD},则()A.\overrightarrow {AD}=- \frac {1}{3} \overrightarrow {AB}+\frac {4}{3} \overrightarrow {A}B.\overrightarrow {AD}= \frac {4}{3} \overrightarrow {AB}- \frac {1}{3} \overrightarrow {AC}C.\overrightarrow {AD}= \frac {2}{3} \overrightarrow {AB}- \frac {1}{2} \overrightarrow {AC}D.\overrightarrow {AD}=- \frac {1}{2} \overrightarrow {AB}+\frac {3}{2} \overrightarrow {AC}4.向量a=(1,-1),b=(-1,2),则(2a+b)\cdot a等于()A.-1B.0C.1D.2Bt:D1::F:O略---B*O1.:表10.若向量a与b的夹角为60^{\circ}, \mid b \mid =4,(a+2b)\cdot(a-3b)=-72,则向量a的模为()A.2B.4C.6D.12二.填空题(每题5分,共20分)11.已知变量x,y满足约束条\cases {x-4y \leqslant -3, \cr 3x+5y \leqslant 25,