1.(5)若xy满足约束条件$\left\{\begin{array}{l}{x-y+2≥0}\\{y+2≥0}\\{x+y+2≤0}\end{array}\right.$,则$\frac{y+1}{x-1}$的取值范围为( )
| A. | [-$\frac{1}{3}$,$\frac{1}{5}$] | B. | [-$\frac{1}{3}$,1] | C. | (-∞,-$\frac{1}{3}$]∪[$\frac{1}{5}$,+∞) | D. | (-∞,-$\frac{1}{3}$]∪[1,+∞) |
18.已知过双曲线C:$\frac{{x}^{2}}{{a}^{2}}$$-\frac{{y}^{2}}{{b}^{2}}$=1(a>0,b>0)的焦点的直线1与C交于A,B两点,且使|AB|=4a的直线1恰好有3条,则双曲线C的渐近线方程为( )
| A. | y=±$\sqrt{2}$x | B. | y=±$\frac{\sqrt{2}}{2}$x | C. | y=±2x | D. | y=±$\frac{1}{2}$x |
16.设全集U=R,集合A={x|-1<x<2},A∩(∁UB)={x|1<x<2},则集合B可以是( )
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| A. | {x|-2<x<2} | B. | {x|-1<x<1} | C. | {x|x≤1} | D. | {x|x>2} |