1.设集合A={x|x≥-1},B={x|y=$\sqrt{3{x}^{2}+5x-2}$},则A∩∁RB等于( )
| A. | {x|-1≤x$<\frac{1}{3}$} | B. | {x|-$\frac{1}{3}<x<2$} | C. | {x|-1$≤x≤\frac{1}{3}$} | D. | {x|-$\frac{1}{3}≤x≤2$} |
19.已知点P(x,y)在不等式组$\left\{\begin{array}{l}{x-2≤0}\\{y-1≤0}\\{x+2y-2≥0}\end{array}\right.$表示的平面区域上运动,则z=x2+y2的取值范围是( )
| A. | [$\frac{3}{5}$,4] | B. | [$\frac{4}{5}$,5] | C. | [$\frac{4}{5}$,6] | D. | [$\frac{3}{5}$,5] |
18.若复数z=$\frac{ai}{1-2i}$(a<0),其中i为虚数单位,|z|=$\sqrt{5}$,则a的值为( )
| A. | -2 | B. | -3 | C. | -4 | D. | -5 |
15.设函数f′(x)是函数f(x)(x∈R)的导函数,f(0)=2,f′(x)-f(x)>ex,则使得f(x)>xex+2ex成立的x的取值范围是( )
| A. | (0,+∞) | B. | (1,+∞) | C. | (0,1) | D. | (-∞,+∞) |
14.已知tanα=-1,且cosα=$\frac{\sqrt{2}}{2}$,则角α为( )
| A. | -$\frac{π}{4}$+kπ,(k∈Z) | B. | -$\frac{π}{4}$+2kπ,(k∈Z) | C. | $\frac{7π}{4}$+2kπ,(k∈Z) | D. | $\frac{3π}{4}$+2kπ,(k∈Z) |
13.tan60°+cot45°-sin90°-cos180°=( )
0 227694 227702 227708 227712 227718 227720 227724 227730 227732 227738 227744 227748 227750 227754 227760 227762 227768 227772 227774 227778 227780 227784 227786 227788 227789 227790 227792 227793 227794 227796 227798 227802 227804 227808 227810 227814 227820 227822 227828 227832 227834 227838 227844 227850 227852 227858 227862 227864 227870 227874 227880 227888 266669
| A. | 2+$\sqrt{3}$ | B. | 1+$\sqrt{3}$ | C. | 3+$\sqrt{3}$ | D. | $\sqrt{3}$ |