14.若数列{an}为等差数列且a1+a7+a13=4π,则sin(a2+a12)的值( )
| A. | $-\frac{{\sqrt{3}}}{2}$ | B. | $\frac{{\sqrt{3}}}{2}$ | C. | 10 | D. | 5 |
13.同时掷两枚骰子,所得点数之和为3的概率为( )
| A. | $\frac{1}{4}$ | B. | $\frac{1}{18}$ | C. | $\frac{1}{6}$ | D. | $\frac{1}{12}$ |
12.抛掷一枚质地均匀的硬币两次,则出现一正一反的概率( )
| A. | $\frac{1}{2}$ | B. | $\frac{1}{3}$ | C. | $\frac{2}{3}$ | D. | $\frac{1}{4}$ |
8.已知集合A={x|x≥-1},则正确的是( )
| A. | 0⊆A | B. | {0}∈A | C. | ∅∈A | D. | {0}⊆A |
7.在下列区间中函数f(x)=2x-4+3x的零点所在的区间为( )
0 233943 233951 233957 233961 233967 233969 233973 233979 233981 233987 233993 233997 233999 234003 234009 234011 234017 234021 234023 234027 234029 234033 234035 234037 234038 234039 234041 234042 234043 234045 234047 234051 234053 234057 234059 234063 234069 234071 234077 234081 234083 234087 234093 234099 234101 234107 234111 234113 234119 234123 234129 234137 266669
| A. | (1,2) | B. | $(0,\frac{1}{2})$ | C. | $(1,\frac{3}{2})$ | D. | $(\frac{1}{2},1)$ |