14.已知双曲线Γ:$\frac{y^2}{a^2}-\frac{x^2}{b^2}=1({a>0,b>0})$的上焦点为F1(0,c)(c>0),下焦点为F2(0,-c)(c>0),过点F1作圆x2+y2-$\frac{2c}{3}y+\frac{a^2}{9}$=0的切线与圆相切于点D,与双曲线下支交于点M,若MF2⊥MF1,则双曲线Γ的渐进线方程为( )
| A. | 4x±y=0 | B. | x±4y=0 | C. | 2x±y=0 | D. | x±2y=0 |
13.已知实数x,y满足$\left\{\begin{array}{l}x≥0\\ y≥0\\ \frac{x}{3}+\frac{y}{4}≤1\end{array}\right.$,则$\frac{y+1}{x+1}$的取值范围是( )
| A. | $[{-\frac{1}{6},5}]$ | B. | [1,5] | C. | $[{\frac{1}{4},5}]$ | D. | [0,5] |
12.已知cos(x-$\frac{π}{3}$)=$\frac{1}{3}$,则cos(2x-$\frac{2π}{3}$)+sin2($\frac{π}{3}$-x)的值为( )
| A. | $-\frac{1}{9}$ | B. | $\frac{1}{9}$ | C. | $\frac{5}{3}$ | D. | $-\frac{5}{3}$ |
8.已知直线a⊥平面α,则“直线b∥平面α”是“直线a⊥直线b”的( )
| A. | 充分不必要条件 | B. | 必要不充分条件 | ||
| C. | 充要条件 | D. | 既不充分也不必要条件 |
7.已知f(x)是定义在R上的奇函数,当x≥0时,f(x)=ex+m(m为常数),则f(m)=( )
| A. | e-1 | B. | 1-e | C. | $1-\frac{1}{e}$ | D. | $\frac{1}{e}-1$ |
6.已知向量$\overrightarrow{a}$,$\overrightarrow{b}$满足|$\overrightarrow{b}$|=2|$\overrightarrow{a}$|,且($\overrightarrow{a}$+$\overrightarrow{b}$)⊥$\overrightarrow{a}$,则$\overrightarrow{a}$,$\overrightarrow{b}$的夹角等于( )
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| A. | $\frac{2π}{3}$ | B. | $\frac{5π}{6}$ | C. | $\frac{π}{3}$ | D. | $\frac{π}{6}$ |