17.已知Ω是由曲线y=$\sqrt{4-{x}^{2}}$与x轴围成的封闭区域,若将质点P(x,y)投入区域Ω中,则x>$\sqrt{3}$y的概率为( )
| A. | $\frac{1}{6}$ | B. | $\frac{1}{3}$ | C. | $\frac{4}{3}$ | D. | $\frac{2}{3}$ |
15.命题“?x∈R,x2≠-1”的否定是( )
| A. | ?x∉R,x2=-1 | B. | ?x∈R,x2=-1 | C. | ?x∉R,x2=-1 | D. | ?x∈R,x2=-1 |
14.若z(2+i)=-i,则|z|=( )
| A. | 2$\sqrt{2}$ | B. | $\frac{1}{5}$ | C. | $\frac{\sqrt{5}}{5}$ | D. | $\sqrt{5}$ |
13.已知A={x|-2≤x≤0},B={x|-1≤x≤1},则A∪B=( )
0 230576 230584 230590 230594 230600 230602 230606 230612 230614 230620 230626 230630 230632 230636 230642 230644 230650 230654 230656 230660 230662 230666 230668 230670 230671 230672 230674 230675 230676 230678 230680 230684 230686 230690 230692 230696 230702 230704 230710 230714 230716 230720 230726 230732 230734 230740 230744 230746 230752 230756 230762 230770 266669
| A. | [-2,1] | B. | [-1,0] | C. | [-2,-1] | D. | [0,1] |