13.不等式-2x2+x<-3的解集是( )
| A. | $({-1,\frac{3}{2}})$ | B. | $({-∞,-1})∪({\frac{3}{2},+∞})$ | C. | $({1,\frac{3}{2}})$ | D. | $({-∞,1})∪({\frac{3}{2},+∞})$ |
12.若函数f(x)=xln(x+$\sqrt{a+{x}^{2}}$)为偶函数,则a的值为( )
| A. | 0 | B. | 1 | C. | -1 | D. | 1或-1 |
9.不等式组x,y满足$\left\{\begin{array}{l}{2x+3y≤0}\\{x-y≥0}\\{y≥-2}\end{array}\right.$,所围成的平面区域面积是( )
| A. | 3 | B. | $\frac{3}{2}$ | C. | $\frac{5}{2}$ | D. | 5 |
8.过两点A(-2,1),B(m,3)的直线倾斜角是45°,则m等于( )
| A. | 0 | B. | 1 | C. | 2 | D. | 4 |
5.已知A,B∈(0,π),那么“A>B”是“cos2A<cos2B”的( )条件.
| A. | 充要 | B. | 充分不必要 | ||
| C. | 必要不充分 | D. | 既不充分也不必要 |
4.与点A(-1,0)和点B(1,0)连线的斜率之和为-1的动点P的轨迹方程是( )
0 233719 233727 233733 233737 233743 233745 233749 233755 233757 233763 233769 233773 233775 233779 233785 233787 233793 233797 233799 233803 233805 233809 233811 233813 233814 233815 233817 233818 233819 233821 233823 233827 233829 233833 233835 233839 233845 233847 233853 233857 233859 233863 233869 233875 233877 233883 233887 233889 233895 233899 233905 233913 266669
| A. | x2+y2=3 | B. | y=$\sqrt{1-{x}^{2}}$ | C. | x2+2xy=1(x≠±1) | D. | x2+y2=9(x≠0) |