8.
函数f(x)=sin(ωx+φ)(x∈R)$(ω>0,|φ|<\frac{π}{2})$的部分图象如图所示,如果${x_1},{x_2}∈(\frac{π}{6},\frac{2π}{3})$,且f(x1)=f(x2),则f(x1+x2)=( )
| A. | $-\frac{{\sqrt{3}}}{2}$ | B. | $-\frac{1}{2}$ | C. | $\frac{1}{2}$ | D. | $\frac{{\sqrt{3}}}{2}$ |
7.△ABC中,tanA,tanB是方程6x2-5x+1=0的两根,则tanC=( )
| A. | -1 | B. | 1 | C. | $-\frac{5}{7}$ | D. | $\frac{5}{7}$ |
3.以椭圆$\frac{x^2}{4}+\frac{y^2}{2}$=1的焦距为实轴,短轴为虚轴的双曲线方程为( )
0 226848 226856 226862 226866 226872 226874 226878 226884 226886 226892 226898 226902 226904 226908 226914 226916 226922 226926 226928 226932 226934 226938 226940 226942 226943 226944 226946 226947 226948 226950 226952 226956 226958 226962 226964 226968 226974 226976 226982 226986 226988 226992 226998 227004 227006 227012 227016 227018 227024 227028 227034 227042 266669
| A. | x2-4y2=2 | B. | x2-y2=2 | C. | x2-2y2=1 | D. | 2x2-y2=1 |