5.已知函数f(x)=sin(ωx+φ)(ω>0,0≤φ≤π)是R上的偶函数,其图象关于点$M(\frac{3π}{4},0)$对称,且在区间$[{0,\frac{π}{2}}]$上是单调函数,则ω的值是( )
| A. | $\frac{2}{3}$ | B. | 2 | C. | $\frac{2}{3}$或2 | D. | 无法确定 |
4.函数$f(x)=sinx-\sqrt{3}cosx(x∈[-π,0])$的单调递增区间是( )
| A. | $[-π,-\frac{5π}{6}]$ | B. | $[-\frac{5π}{6},-\frac{π}{6}]$ | C. | $[-\frac{π}{6},0]$ | D. | $[-\frac{π}{3},0]$ |
20.命题“?x0∈R,${x_0}^2-{x_0}+1≤0$”的否定为( )
| A. | ?x0∈R,${x_0}^2-{x_0}+1≤0$ | B. | ?x0∈R,${x_0}^2-{x_0}+1>0$ | ||
| C. | ?x∈R,x2-x+1≤0 | D. | ?x∈R,x2-x+1>0 |
18.公差为正数的等差数列{an}的前n项和为Sn,S3=18,且已知a1、a4的等比中项是6,求S10=( )
| A. | 145 | B. | 165 | C. | 240 | D. | 600 |
17.已知函数$f(x)=a{x^3}-\frac{3}{2}{x^2}+1(a>0)$在区间[-$\frac{1}{2}$,$\frac{1}{2}$]上有f(x)>0恒成立,则a的取值范围为( )
0 240656 240664 240670 240674 240680 240682 240686 240692 240694 240700 240706 240710 240712 240716 240722 240724 240730 240734 240736 240740 240742 240746 240748 240750 240751 240752 240754 240755 240756 240758 240760 240764 240766 240770 240772 240776 240782 240784 240790 240794 240796 240800 240806 240812 240814 240820 240824 240826 240832 240836 240842 240850 266669
| A. | (0,2] | B. | [2,+∞) | C. | (0,5) | D. | (2,5] |