15.设U=R,集合M={-1,1,2},N={x|-1<x<2},则N∩M=( )
| A. | {-1,2} | B. | {1} | C. | {2} | D. | {-1,1,2} |
14.$\frac{3+i}{1-i}$的虚部为( )
| A. | 2 | B. | -2 | C. | -2i | D. | 2i |
13.已知向量$\overrightarrow{a}$,$\overrightarrow{b}$满足$\overrightarrow{a}$⊥$\overrightarrow{b}$,|$\overrightarrow{a}$|=2,|$\overrightarrow{b}$|=3,且3$\overrightarrow{a}$+2$\overrightarrow{b}$与λ$\overrightarrow{a}$-$\overrightarrow{b}$垂直,则实数λ的值为( )
| A. | $\frac{3}{2}$ | B. | -$\frac{3}{2}$ | C. | ±$\frac{3}{2}$ | D. | 1 |
12.下列函数中,既是偶函数,又是区间(0,3)内是增函数的是( )
| A. | y=log${\;}_{\frac{1}{2}}$|x| | B. | y=cosx | C. | y=ex+e-x | D. | y=x+$\frac{1}{x}$ |
11.设复数z满足(3-4i)z=|4+3i|(i是虚数单位),则复数z的虚部是( )
| A. | 4 | B. | 4i | C. | $\frac{4}{5}$i | D. | $\frac{4}{5}$ |
10.已知集合P={x|-x2+2x≤0},Q={x|1<x≤3},则(∁RP)∩Q等于( )
| A. | [1,3] | B. | (2,3] | C. | (1,2) | D. | [1,2] |
8.已知单位向量$\overrightarrow{a}$,$\overrightarrow{b}$满足$\overrightarrow{a}$•($\overrightarrow{a}$-2$\overrightarrow{b}$)=2,则向量$\overrightarrow{a}$与$\overrightarrow{b}$的夹角为( )
0 227738 227746 227752 227756 227762 227764 227768 227774 227776 227782 227788 227792 227794 227798 227804 227806 227812 227816 227818 227822 227824 227828 227830 227832 227833 227834 227836 227837 227838 227840 227842 227846 227848 227852 227854 227858 227864 227866 227872 227876 227878 227882 227888 227894 227896 227902 227906 227908 227914 227918 227924 227932 266669
| A. | 120° | B. | 90° | C. | 60° | D. | 30° |