14.下列各组函数中,表示同一函数的是( )
| A. | f(x)=x+1,g(x)=$\frac{x^2}{x}$-1 | B. | f(x)=|x|,g(x)=($\sqrt{x}$)2 | ||
| C. | f(x)=2log2x,g(x)=log2x2 | D. | f(x)=x,g(x)=log22x |
8.若一个几何体各个顶点或其外轮廓曲线都在某个球的球面上,那么称这个几何体内接于该球,已知球的体积为$\frac{32π}{3}$,那么下列可以内接于该球的几何体为( )
| A. | 底面半径为1,且体积为$\frac{4π}{3}$的圆锥 | B. | 底面积为1,高为$\sqrt{14}$的正四棱柱 | ||
| C. | 棱长为3的正四面体 | D. | 棱长为3的正方体 |
7.已知实数x,y满足不等式组$\left\{\begin{array}{l}{x≤1}\\{y≤2}\\{2x+y-2≥0}\end{array}\right.$,那么|x-y|的最大值是( )
| A. | 1 | B. | 2 | C. | 3 | D. | 4 |
6.已知直线l1:(k-1)x+y+2=0和直线l2:8x+(k+1)y+k-1=0平行,则k的值是( )
| A. | 3 | B. | -3 | C. | 3或-3 | D. | $\sqrt{7}$或-$\sqrt{7}$ |
5.已知向量$\overrightarrow{a}$=(cosθ,-sinθ),$\overrightarrow{b}$=(3cosθ,sinθ),θ∈(0,π),若$\overrightarrow{a}$⊥$\overrightarrow{b}$,则θ=( )
0 233635 233643 233649 233653 233659 233661 233665 233671 233673 233679 233685 233689 233691 233695 233701 233703 233709 233713 233715 233719 233721 233725 233727 233729 233730 233731 233733 233734 233735 233737 233739 233743 233745 233749 233751 233755 233761 233763 233769 233773 233775 233779 233785 233791 233793 233799 233803 233805 233811 233815 233821 233829 266669
| A. | $\frac{π}{3}$ | B. | $\frac{2π}{3}$ | C. | $\frac{π}{6}$或$\frac{5π}{6}$ | D. | $\frac{π}{3}$或$\frac{2π}{3}$ |