10.已知函数y=sinx+acosx的图象关于x=$\frac{π}{3}$对称,则函数y=asinx+cosx的图象的一条对称轴是( )
| A. | x=$\frac{5π}{6}$ | B. | x=$\frac{2π}{3}$ | C. | x=$\frac{π}{3}$ | D. | x=$\frac{π}{6}$ |
5.已知全集U={1,2,3,4,5,6},集合P={1,3,5},Q={1,2,4},则(∁UP)∩Q=( )
| A. | {3,5} | B. | {2,4} | C. | {1,2,4,6} | D. | {1,2,3,4,5} |
3.下列命题中,正确的是( )
| A. | 命题“?x∈R,x2-x≤0”的否定是“$?{x_0}∈R,x_0^2-{x_0}≥0$”. | |
| B. | 命题“p∧q为真”是命题“p∨q为真”的必要不充分条件. | |
| C. | “若am2≤bm2,则a≤b”的否命题为真. | |
| D. | 若实数x,y∈[-1,1],则满足x2+y2≥1的概率为$\frac{π}{4}$. |
2.已知函数f(x)=|x-a|,g(x)=f(x)+f(x+2).
(Ⅰ)当a=-1时,解不等式:f(x)≥4-|2x-1|;
(Ⅱ)若关于x的不等式f(x)≤1的解集为[0,2],求证:g(x)≥2.
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(Ⅰ)当a=-1时,解不等式:f(x)≥4-|2x-1|;
(Ⅱ)若关于x的不等式f(x)≤1的解集为[0,2],求证:g(x)≥2.