17.定义在R上的函数y=f(x)是奇函数,且x≥0时,f(x)=ln(x2-2x+2),则x<0时,f(x)的解析式是( )
| A. | f(x)=ln(-x2-2x+2) | B. | f(x)=ln(x2+2x+2) | C. | f(x)=-ln(-x2-2x+2) | D. | f(x)=-ln(x2+2x+2) |
9.等比数列{an}中,${a_1}+{a_2}+{a_3}+…+{a_n}={2^n}-1$,则$\frac{1}{a_1^2}+\frac{1}{a_2^2}+\frac{1}{a_3^2}+…+\frac{1}{a_n^2}$=( )
| A. | (2n-1)2 | B. | $\frac{1}{3}({2^n}-1)$ | C. | $\frac{1}{3}(4-\frac{1}{{{4^{n-1}}}})$ | D. | $\frac{1}{3}({4^n}-1)$ |
8.已知变量x、y满足$\left\{\begin{array}{l}{x-4y+3≤0}\\{3x+5y<25}\\{x≥1}\end{array}\right.$,则目标函数z=2x+y的最小值为( )
0 224912 224920 224926 224930 224936 224938 224942 224948 224950 224956 224962 224966 224968 224972 224978 224980 224986 224990 224992 224996 224998 225002 225004 225006 225007 225008 225010 225011 225012 225014 225016 225020 225022 225026 225028 225032 225038 225040 225046 225050 225052 225056 225062 225068 225070 225076 225080 225082 225088 225092 225098 225106 266669
| A. | 1 | B. | 3 | C. | 5 | D. | $\frac{15}{2}$ |