15.若方程x3-3x+m=0在[0,2]上只有一个解,则实数m的取值范围是( )
| A. | [-2,2] | B. | (0,2] | C. | [-2,0)∪{2} | D. | (-∞,-2)∪(2,+∞) |
14.已知圆的方程为x2+y2-2y-4=0,过点A(2,1)的直线被圆所截,则截得的最短弦的长度为( )
| A. | $\frac{3}{2}$ | B. | 2 | C. | $\frac{{3\sqrt{2}}}{2}$ | D. | $2\sqrt{2}$ |
11.若直线x+my-2=0的倾斜角为30°,则实数m的值是( )
| A. | -$\frac{\sqrt{3}}{3}$ | B. | $\frac{\sqrt{3}}{3}$ | C. | -$\sqrt{3}$ | D. | $\sqrt{3}$ |
8.下列函数中,是奇函数且在区间(0,1)内单调递减的函数是( )
0 225793 225801 225807 225811 225817 225819 225823 225829 225831 225837 225843 225847 225849 225853 225859 225861 225867 225871 225873 225877 225879 225883 225885 225887 225888 225889 225891 225892 225893 225895 225897 225901 225903 225907 225909 225913 225919 225921 225927 225931 225933 225937 225943 225949 225951 225957 225961 225963 225969 225973 225979 225987 266669
| A. | y=log2x | B. | y=x-$\frac{1}{x}$ | C. | y=-x3 | D. | y=tanx |