16.设x,y满足条件$\left\{\begin{array}{l}x+y-2≥0\\ x-y-2≤0\\ y≤2\end{array}\right.$,则z=2x+3y的最小值是( )
| A. | 4 | B. | 6 | C. | 10 | D. | 14 |
15.在△ABC中,若BC=$\sqrt{2}$,AC=2,B=45°,则角A等于( )
| A. | 60° | B. | 30° | C. | 60°或120° | D. | 30°或150° |
13.等差数列{an}的前n项和为Sn,已知(a1007-1)3+2 015(a1007-1)=1,(a1009-1)3+2 015(a1009-1)=-1,则( )
| A. | S2015=2 015,a1009>1>a1007 | B. | S2015=2 015,a1007>1>a1009 | ||
| C. | S2015=-2 015,a1009>1>a1007 | D. | S2015=-2 015,a1007>1>a1009 |
11.已知集合A={1,2,3},那么A的真子集的个数是( )
| A. | 8 | B. | 7 | C. | 6 | D. | 3 |
10.函数f(x)=x2-2kx-8在区间[0,14]上为增函数,则实数k的取值范围为( )
| A. | (-∞,0) | B. | (-∞,0] | C. | (0,+∞) | D. | [0,+∞) |
9.若f(x)的定义域为[-3,2],则函数y=f(-2x+1)的定义域为( )
| A. | [-3,7] | B. | $[{-\frac{1}{2}\;,\;\;2}]$ | C. | [-3,2] | D. | [-1,2] |
8.若指数函数f(x)=ax在区间[0,2]上的最大值与最小值之和为10,则a的值为( )
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| A. | $\frac{1}{3}$ | B. | 3 | C. | ±3 | D. | $±\frac{1}{3}$ |