5.若复数z满足z(1+2i)=2,则z的虚部为( )
| A. | $-\frac{4}{5}$ | B. | $\frac{4}{5}$ | C. | $-\frac{4}{5}i$ | D. | $\frac{4}{5}i$ |
4.已知集合A={x|(x-2)(x+1)<0},B={x∈Z|-1≤x≤1},则A∩B=( )
| A. | {-1,0} | B. | {0,1} | C. | {-1,0,1} | D. | {-1,2} |
19.已知点P是△ABC所在平面外一点,点O是点P在平面ABC上的射影,在下列条件下:P到△ABC三个顶点距离相等;P到△ABC三边距离相等;AP、BP、CP两两互相垂直,点O分别是△ABC的( )
| A. | 垂心,外心,内心 | B. | 外心,内心,垂心 | C. | 内心,外心,垂心 | D. | 内心,垂心,外心 |
18.圆心是点C(2,-3)且经过原点的圆的方程是( )
| A. | (x+2)2+(y-3)2=13 | B. | (x+2)2+(y+3)2=$\sqrt{13}$ | C. | (x+2)2+(y-3)2=$\sqrt{13}$ | D. | (x-2)2+(y+3)2=13 |
16.已知全集I={1,2,3,4,5,6,7,8},集合M={3,4,5},集合N={1,3,6},则集合{2,7,8}是( )
0 234034 234042 234048 234052 234058 234060 234064 234070 234072 234078 234084 234088 234090 234094 234100 234102 234108 234112 234114 234118 234120 234124 234126 234128 234129 234130 234132 234133 234134 234136 234138 234142 234144 234148 234150 234154 234160 234162 234168 234172 234174 234178 234184 234190 234192 234198 234202 234204 234210 234214 234220 234228 266669
| A. | M∪N | B. | M∩N | C. | ∁IM∪∁IN | D. | ∁IM∩∁IN |