1.已知函数$f(x)={log_a}({x^2}+2x-3)$,若f(2)<0,则此函数的单调递增区间是( )
| A. | (1,+∞)∪(-∞,-3) | B. | (1,+∞) | C. | (-∞,-1) | D. | (-∞,-3) |
20.若幂函数f(x)的图象过点(2,8),则f(3)的值为( )
| A. | 6 | B. | 9 | C. | 16 | D. | 27 |
19.已知集合A={-1,0,1},B={-2,-1,0},则A∩B等于( )
| A. | {0} | B. | {-1,0,1} | C. | {0,1} | D. | {-1,0} |
18.已知函数f(x)=$\sqrt{3}$sinωxcosωx-cos2ωx-$\frac{1}{2}$(x∈R,ω>0),若f(x)的图象中相邻的两条对称轴之间的距离不小于$\frac{π}{2}$,则ω的取值范围是( )
| A. | (0,1) | B. | (0,1] | C. | (0,2) | D. | (0,2] |
17.已知A={2,3,4},B={x||x|<3},则A∩B=( )
| A. | {3} | B. | {2,3} | C. | {2} | D. | {2,3,4} |
16.设全集U={x∈Z|-2<x<4},集合S与T都为U的子集,S∩T={2},(∁US)∩T={-1},(∁US)∩(∁UT)={1,3},则下列说法正确的是( )
| A. | 0属于S,且0属于T | B. | 0属于S,且0不属于T | ||
| C. | 0不属于S但0属于T | D. | 0不属于S,也不属于T |
13.直线y=mx+2过双曲线$\frac{{x}^{2}}{2}$-y2=1的顶点,则m等于( )
0 224066 224074 224080 224084 224090 224092 224096 224102 224104 224110 224116 224120 224122 224126 224132 224134 224140 224144 224146 224150 224152 224156 224158 224160 224161 224162 224164 224165 224166 224168 224170 224174 224176 224180 224182 224186 224192 224194 224200 224204 224206 224210 224216 224222 224224 224230 224234 224236 224242 224246 224252 224260 266669
| A. | 0 | B. | ±$\sqrt{2}$ | C. | ±$\frac{\sqrt{2}}{2}$ | D. | ±$\frac{1}{2}$ |