10.设f(x)是以1为周期的偶函数,且$f(-\frac{2}{5})=3$,若$sinα=\frac{{\sqrt{5}}}{5}$,则f(cos2α)的值是( )
| A. | -3 | B. | 3 | C. | $-\frac{{\sqrt{5}}}{5}$ | D. | $\frac{{\sqrt{5}}}{5}$ |
8.己知角α的顶点在原点,始边与x轴正半轴重合,终边为射线4x+3y=0(x>0),sinα(sinα+cotα)+cos2α的值是( )
| A. | $\frac{1}{5}$ | B. | $\frac{2}{5}$ | C. | $\frac{8}{5}$ | D. | $\frac{9}{5}$ |
6.已知a=logπe,b=($\sqrt{6}$)-2,c=$\frac{1}{ln2}$,则a,b,c的大小关系为( )
| A. | c>b>a | B. | c>a>b | C. | a>b>c | D. | a>c>b |
4.方程lnx=$\frac{x+1}{x-1}$实数根的个数为( )
0 225715 225723 225729 225733 225739 225741 225745 225751 225753 225759 225765 225769 225771 225775 225781 225783 225789 225793 225795 225799 225801 225805 225807 225809 225810 225811 225813 225814 225815 225817 225819 225823 225825 225829 225831 225835 225841 225843 225849 225853 225855 225859 225865 225871 225873 225879 225883 225885 225891 225895 225901 225909 266669
| A. | 0 | B. | 1 | C. | 2 | D. | 3 |