4.动点P到两定点F1(0,-4),F2(0,4)的距离之和为10,则动点P的轨迹方程是( )
| A. | $\frac{x^2}{16}+\frac{y^2}{9}=1$ | B. | $\frac{x^2}{9}+\frac{y^2}{25}=1$ | C. | $\frac{x^2}{16}+\frac{y^2}{25}=1$ | D. | $\frac{x^2}{100}+\frac{y^2}{36}=1$ |
2.下列函数中,既是奇函数,又在(1,+∞)上递增的是( )
0 226797 226805 226811 226815 226821 226823 226827 226833 226835 226841 226847 226851 226853 226857 226863 226865 226871 226875 226877 226881 226883 226887 226889 226891 226892 226893 226895 226896 226897 226899 226901 226905 226907 226911 226913 226917 226923 226925 226931 226935 226937 226941 226947 226953 226955 226961 226965 226967 226973 226977 226983 226991 266669
| A. | y=x3-6x | B. | y=x2-2x | C. | y=sinx | D. | y=x3-3x |