12.
函数f(x)=Asinωx(A>0,ω>0)的部分图象如图所示,则f(1)+f(2)+f(3)+…+f(2019)的值为( )
| A. | $\sqrt{2}$+1 | B. | 2+2$\sqrt{2}$ | C. | 2+$\sqrt{2}$ | D. | -2-2$\sqrt{2}$ |
11.若直线mx-y-1=0与直线x-2y+3=0垂直,则m的值为( )
| A. | $\frac{1}{2}$ | B. | -$\frac{1}{2}$ | C. | 2 | D. | -2 |
10.已知集合A={1,2,3},B={3,4},则A∪B=( )
| A. | {1,2} | B. | {1,2,3,4} | C. | {1,2,3} | D. | {1,2,4} |
7.若点(a,9)在函数y=3x的图象上,则y=loga(x2+2x+5)的最小值为( )
0 227733 227741 227747 227751 227757 227759 227763 227769 227771 227777 227783 227787 227789 227793 227799 227801 227807 227811 227813 227817 227819 227823 227825 227827 227828 227829 227831 227832 227833 227835 227837 227841 227843 227847 227849 227853 227859 227861 227867 227871 227873 227877 227883 227889 227891 227897 227901 227903 227909 227913 227919 227927 266669
| A. | 0 | B. | 2log32 | C. | 2 | D. | log25 |