8.已知x,y满足约束条件$\left\{\begin{array}{l}{x≥1}\\{y≥-1}\\{4x+y≤9}\\{x+y≤3}\end{array}\right.$,若2≤m≤4,则目标函数z=y+mx的最大值的变化范围是( )
| A. | [1,3] | B. | [4,6] | C. | [4,9] | D. | [5,9] |
6.将由曲线y=cosx,直线x=0,x=π,y=0所围成图形的面积写成定积分的形式为( )
| A. | ${∫}_{0}^{π}$cosxdx | B. | ${∫}_{0}^{\frac{π}{2}}$cosxdx+|${∫}_{\frac{π}{2}}^{π}$cosxdx| | ||
| C. | ${∫}_{0}^{π}$2sinxdx | D. | ${∫}_{0}^{π}$2|cosx|dx |
4.${∫}_{0}^{1}$|x2-8|dx=( )
| A. | $\frac{21}{3}$ | B. | $\frac{22}{3}$ | C. | $\frac{23}{3}$ | D. | $\frac{25}{3}$ |
3.由曲线y=x3,直线x=0,x=1及y=0所围成的曲边梯形的面积为( )
| A. | 1 | B. | $\frac{1}{2}$ | C. | $\frac{1}{3}$ | D. | $\frac{1}{4}$ |
1.设实数x,y满足约束条件$\left\{\begin{array}{l}{x-y-1≤0}\\{x+y-1≤0}\\{x≥-1}\end{array}\right.$,则x2+(y+2)2的取值范围是( )
0 226636 226644 226650 226654 226660 226662 226666 226672 226674 226680 226686 226690 226692 226696 226702 226704 226710 226714 226716 226720 226722 226726 226728 226730 226731 226732 226734 226735 226736 226738 226740 226744 226746 226750 226752 226756 226762 226764 226770 226774 226776 226780 226786 226792 226794 226800 226804 226806 226812 226816 226822 226830 266669
| A. | [$\frac{1}{2}$,17] | B. | [1,17] | C. | [1,$\sqrt{17}$] | D. | [$\frac{\sqrt{2}}{2}$,$\sqrt{17}$] |