13.已知i是虚数单位,则i(1-i)2=( )
| A. | 2-2i | B. | 2+2i | C. | -2 | D. | 2 |
12.(1-x)6(1+x)4的展开式中x2的系数是( )
| A. | -4 | B. | -3 | C. | 3 | D. | 4 |
11.设Ω为不等式组$\left\{\begin{array}{l}{x+y≥0}\\{x-y+4≥0}\\{x≤m}\end{array}\right.$(m>0)表示的平面区域.若Ω的面积为9,则m=( )
| A. | 8 | B. | 6 | C. | 4 | D. | 1 |
10.数列{an}中${a_1}=\frac{1}{2},{a_{n+1}}=\frac{a_n}{{1+3{a_n}}}$,记数列$\{\frac{1}{a_n}\}$的前n项和为Tn,则T8的值为( )
| A. | 57 | B. | 77 | C. | 100 | D. | 126 |
9.若双曲线$\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$(a>0,b>0)的一条渐近线方程是3x+2y=0,则它的离心率等于( )
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| A. | $\frac{{\sqrt{5}}}{2}$ | B. | $\frac{{\sqrt{5}}}{3}$ | C. | $\frac{{\sqrt{13}}}{2}$ | D. | $\frac{{\sqrt{13}}}{3}$ |