19.设集合A={1,3},集合B={1,2,5},则集合A∪B=( )
A. | {1,2,5} | B. | {1} | C. | {1,2,3,5} | D. | {2,3,5} |
17.函数y=x2-2x-1,x∈[0,3]的值域为( )
0 251758 251766 251772 251776 251782 251784 251788 251794 251796 251802 251808 251812 251814 251818 251824 251826 251832 251836 251838 251842 251844 251848 251850 251852 251853 251854 251856 251857 251858 251860 251862 251866 251868 251872 251874 251878 251884 251886 251892 251896 251898 251902 251908 251914 251916 251922 251926 251928 251934 251938 251944 251952 266669
A. | [-1,2] | B. | [-2,2] | C. | [-2,-1] | D. | [-1,1] |