11.已知直线y=x+1与曲线y=f(x)=ln(x+a)相切,则${∫}_{1}^{2}$f′(x-2)dx=( )
| A. | 1 | B. | ln2 | C. | 2ln2 | D. | 2 |
6.实数a,b,c满足$\left\{\begin{array}{l}{a>0}\\{{b}^{2}=ac}\\{5b≥2(a+c)}\end{array}\right.$,则$\frac{5a+8b+4c}{a+b}$的取值范围是( )
0 227701 227709 227715 227719 227725 227727 227731 227737 227739 227745 227751 227755 227757 227761 227767 227769 227775 227779 227781 227785 227787 227791 227793 227795 227796 227797 227799 227800 227801 227803 227805 227809 227811 227815 227817 227821 227827 227829 227835 227839 227841 227845 227851 227857 227859 227865 227869 227871 227877 227881 227887 227895 266669
| A. | [$\frac{5}{12}$,$\frac{11}{6}$] | B. | (-∞,$\frac{5}{12}$]∪[$\frac{11}{6}$,+∞) | C. | [$\frac{20}{3}$,$\frac{37}{3}$] | D. | (-∞,$\frac{20}{3}$]∪[$\frac{37}{3}$,+∞) |