13.若P(x,y)在不等式组$\left\{\begin{array}{l}{3x+y-8≤0}\\{x+2y-1≥0}\\{2x-y-2≥0}\end{array}\right.$所表示的平面区域内,则|2x+y+3|的最小值为( )
| A. | $\sqrt{2}$ | B. | $\frac{\sqrt{10}}{2}$ | C. | 5 | D. | 4 |
12.已知i是虚数单位,若复数z满足z=$\frac{{i}^{3}}{1+i}$,则z的共轭复数$\overline{z}$为( )
| A. | $\frac{1+i}{2}$ | B. | $\frac{1-i}{2}$ | C. | $\frac{-1+i}{2}$ | D. | $\frac{-1-i}{2}$ |
11.设集合A={x|-x2+2x+3>0},B={x|$\frac{1}{4}$<($\frac{1}{2}$)x<1},则A∩B=( )
| A. | (0,3) | B. | (0,2) | C. | (1,3) | D. | (1,+∞) |
10.复数$\frac{1}{1+2i}$的虚部为( )
| A. | $\frac{1}{5}$i | B. | $\frac{1}{5}$ | C. | -$\frac{2}{5}$ | D. | -$\frac{2}{5}$i |
9.已知全集U=R,P=(0,1],Q={x|2x≤1},则P∪Q=( )
| A. | (-∞,1) | B. | (1,+∞) | C. | (-∞,1] | D. | [1,+∞) |
6.在△ABC中,AB=AC,M为AC的中点,BM=$\sqrt{3}$,则△ABC面积的最大值是( )
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| A. | $\sqrt{2}$ | B. | 2 | C. | $\frac{3}{2}$ | D. | 3 |