8.若实数x,y满足不等式组$\left\{\begin{array}{l}{x+3y-3≥0}\\{2x-y-3≤0}\\{x-my+1≥0}\end{array}\right.$,且x+y的最大值为4,则实数m=( )
A. | -1 | B. | 0 | C. | 1 | D. | 2 |
6.下列函数中,在定义域内与函数y=x3的单调性,奇偶性都相同的是( )
0 249690 249698 249704 249708 249714 249716 249720 249726 249728 249734 249740 249744 249746 249750 249756 249758 249764 249768 249770 249774 249776 249780 249782 249784 249785 249786 249788 249789 249790 249792 249794 249798 249800 249804 249806 249810 249816 249818 249824 249828 249830 249834 249840 249846 249848 249854 249858 249860 249866 249870 249876 249884 266669
A. | y=sinx | B. | y=x3-x | C. | y=2x | D. | y=lg(x+$\sqrt{{x}^{2}+1}$) |