18.若椭圆$\frac{x^2}{a^2}$+$\frac{y^2}{b^2}$=1(a>b>0)的离心率为$\frac{{\sqrt{3}}}{2}$,则$\frac{a}{b}$=( )
| A. | 3 | B. | $\sqrt{2}$ | C. | $\sqrt{3}$ | D. | 2 |
17.双曲线$\frac{x^2}{2}$-$\frac{y^2}{3}$=1的焦点到其渐近线距离为( )
| A. | 1 | B. | $\sqrt{2}$ | C. | $\sqrt{3}$ | D. | 2 |
16.若f(x)=xcosx,则函数f(x)的导函数f'(x)等于( )
| A. | 1-sinx | B. | x-sinx | C. | sinx+xcosx | D. | cosx-xsinx |
15.抛物线y2=6x的焦点到准线的距离为( )
| A. | 1 | B. | 2 | C. | 3 | D. | 4 |
13.已知复数z=a+i,若z+$\overline z$=4,则复数z的共轭复数$\overline z$=( )
| A. | 2+i | B. | 2-i | C. | -2+i | D. | -2-i |
12.已知函数f(x)=$\left\{\begin{array}{l}{{2}^{x-2}-1,x≥0}\\{x+2,x<0}\end{array}\right.$,g(x)=x2-2x,则函数f[g(x)]的所有零点之和是( )
0 233605 233613 233619 233623 233629 233631 233635 233641 233643 233649 233655 233659 233661 233665 233671 233673 233679 233683 233685 233689 233691 233695 233697 233699 233700 233701 233703 233704 233705 233707 233709 233713 233715 233719 233721 233725 233731 233733 233739 233743 233745 233749 233755 233761 233763 233769 233773 233775 233781 233785 233791 233799 266669
| A. | 2 | B. | 2$\sqrt{3}$ | C. | 1+$\sqrt{3}$ | D. | 0 |