12.若函数f(x)=x3-12x在区间(k-1,k+1)上不是单调函数,则实数k的取值范围( )
| A. | k≤-3或-1≤k≤1或k≥3 | B. | 不存在这样的实数k | ||
| C. | -2<k<2 | D. | -3<k<-1或1<k<3 |
11.已知集合A={x|x2-6x+5<0},B={x|$\frac{1}{4}$<2x-4<16},C={x|-a<x≤a+3}
(1)求A∪B和(∁RA)∩B
(2)若A∪C=A,求实数a的取值范围.
(1)求A∪B和(∁RA)∩B
(2)若A∪C=A,求实数a的取值范围.
10.A={1,2,3},b={a,b},则从A到B的可以构成映射的个数( )
| A. | 4个 | B. | 6个 | C. | 8个 | D. | 9 个 |
9.下列式子中成立的是( )
| A. | log0.34<log0.36 | B. | 1.72.4>1.72.5 | C. | 2.50.2<2.40.2 | D. | log34>log43 |
7.已知x,y满足不等式组$\left\{\begin{array}{l}{x≥1}\\{x-y-1≤0}\\{2x+y-5≤0}\end{array}\right.$,则z=-3x-y的最小值为( )
| A. | -3 | B. | -7 | C. | -6 | D. | -8 |
6.已知θ∈($\frac{π}{2}$,π),sinθ=$\frac{3}{5}$,则sin(θ+$\frac{5π}{2}$)等于( )
0 234080 234088 234094 234098 234104 234106 234110 234116 234118 234124 234130 234134 234136 234140 234146 234148 234154 234158 234160 234164 234166 234170 234172 234174 234175 234176 234178 234179 234180 234182 234184 234188 234190 234194 234196 234200 234206 234208 234214 234218 234220 234224 234230 234236 234238 234244 234248 234250 234256 234260 234266 234274 266669
| A. | $\frac{3}{5}$ | B. | -$\frac{3}{5}$ | C. | $\frac{4}{5}$ | D. | -$\frac{4}{5}$ |