17.定义在R上的偶函数f(x)满足:对任意的x1,x2∈(-∞,0)(x1≠x2),都有$\frac{{f({x_1})-f({x_2})}}{{{x_1}-{x_2}}}>0$.则下列结论正确的是( )
| A. | $f({log_2}^{\frac{1}{4}})>f({0.2^3})>f(\sqrt{3})$ | B. | $f({log_2}^{\frac{1}{4}})>f(\sqrt{3})>f({0.2^3})$ | ||
| C. | $f(\sqrt{3})>f({0.2^3})>f({log_2}^{\frac{1}{4}})$ | D. | $f({0.2^3})>f(\sqrt{3})>f({log_2}^{\frac{1}{4}})$ |
16.已知函数$f(x)=3sin(ωx+φ)(|φ|<\frac{π}{2})$的最小正周期为π,且f(x)的图象经过点$(-\frac{π}{6},0)$.则函数f(x)的图象的一条对称轴方程为( )
| A. | $x=\frac{5π}{12}$ | B. | $x=-\frac{π}{12}$ | C. | $x=-\frac{5π}{12}$ | D. | $x=\frac{π}{2}$ |
15.命题p:?x∈(-∞,0),2x>3x;命题q:?x∈(0,+∞),$\sqrt{x}$>x3; 则下列命题中真命题是( )
| A. | p∧q | B. | (¬p)∧q | C. | (¬p)∨(¬q) | D. | p∧(¬q) |
14.已知$f(x)=\left\{\begin{array}{l}{log_3}x,x>0\\{2^{-x}},x≤0\end{array}\right.$,则$f(\frac{1}{9})+f({log_2}^{\frac{1}{6}})$=( )
| A. | $-\frac{11}{6}$ | B. | -8 | C. | 4 | D. | 8 |
13.设x,y∈R,则x2(x-y)>0是x>y的( )
| A. | 充分非必要条件 | B. | 必要非充分条件 | ||
| C. | 充要条件 | D. | 既不充分也不必要条件 |
12.已知复数z=2+i(i虚数单位),若$\frac{a}{z}+{z^2}∈R$,则实数a的值为( )
| A. | 4 | B. | 10 | C. | 20 | D. | $-\frac{15}{2}$ |
11.已知集合A={x|-1≤x≤1},B={x|x2-1>0},则下列结论中正确的是( )
0 252586 252594 252600 252604 252610 252612 252616 252622 252624 252630 252636 252640 252642 252646 252652 252654 252660 252664 252666 252670 252672 252676 252678 252680 252681 252682 252684 252685 252686 252688 252690 252694 252696 252700 252702 252706 252712 252714 252720 252724 252726 252730 252736 252742 252744 252750 252754 252756 252762 252766 252772 252780 266669
| A. | A?B | B. | A∪B=A | C. | A∩B=B | D. | ∁RB=A |