19.已知函数f(x)=sin(ωx-$\frac{π}{6}$)(ω>0)在区间[-$\frac{π}{2}$,$\frac{4π}{3}$]上单调递增,则实数ω的最大值为( )
| A. | 2 | B. | $\frac{3}{2}$ | C. | 1 | D. | $\frac{1}{2}$ |
18.在数列{an}中,a1=1,若an-an-1=n-1(n∈N*,n≥2),则数列{an}的通项公式an=( )
| A. | $\frac{n(n+1)}{2}$ | B. | $\frac{{n}^{2}-n+2}{2}$ | C. | 2n2-n | D. | 2n-1 |
14.已知过双曲线$\frac{{x}^{2}}{{a}^{2}}$-$\frac{{y}^{2}}{{b}^{2}}$=1(a>0,b>0)的右焦点且垂直于x轴的直线l与双曲线的渐近线围成的三角形面积为$\frac{4\sqrt{3}}{3}$,双曲线的离心率为$\frac{2}{3}$$\sqrt{3}$,则双曲线的标准方程是( )
0 227820 227828 227834 227838 227844 227846 227850 227856 227858 227864 227870 227874 227876 227880 227886 227888 227894 227898 227900 227904 227906 227910 227912 227914 227915 227916 227918 227919 227920 227922 227924 227928 227930 227934 227936 227940 227946 227948 227954 227958 227960 227964 227970 227976 227978 227984 227988 227990 227996 228000 228006 228014 266669
| A. | $\frac{{x}^{2}}{3}$-y2=1 | B. | $\frac{{y}^{2}}{3}$-x2=1 | C. | x2-$\frac{{y}^{2}}{3}$=1 | D. | y2-$\frac{{x}^{2}}{3}$=1 |