7.设复数z满足(1+2i)z=5i,则复数z为( )
| A. | 2+i | B. | -2+i | C. | 2-i | D. | -2-i |
6.已知一次函数f(x)=ax-1满足a∈[-1,2]且a≠0,那么对于a,使得f(x)≤0在x∈[0,1]上成立的概率为( )
| A. | $\frac{3}{4}$ | B. | $\frac{2}{3}$ | C. | $\frac{1}{2}$ | D. | $\frac{1}{3}$ |
1.
如图,三棱柱ABC-A1B1C1的棱长都相等,侧棱垂直于底面,点D是棱AB的中点,则直线AC与平面A1DC所成角的正弦值为( )
0 224980 224988 224994 224998 225004 225006 225010 225016 225018 225024 225030 225034 225036 225040 225046 225048 225054 225058 225060 225064 225066 225070 225072 225074 225075 225076 225078 225079 225080 225082 225084 225088 225090 225094 225096 225100 225106 225108 225114 225118 225120 225124 225130 225136 225138 225144 225148 225150 225156 225160 225166 225174 266669
| A. | $\frac{\sqrt{5}}{5}$ | B. | $\frac{\sqrt{2}}{2}$ | C. | $\frac{\sqrt{2}}{4}$ | D. | $\frac{\sqrt{6}}{4}$ |