10.已知平面向量$\overrightarrow{a}$和$\overrightarrow{b}$的夹角为60°,$\overrightarrow{a}$=(0,1),|$\overrightarrow{b}$|=2,则|2$\overrightarrow{a}$+$\overrightarrow{b}$|=( )
| A. | 2 | B. | 12 | C. | $\sqrt{3}$ | D. | 2$\sqrt{3}$ |
9.已知数列{an}满足a1=1,且anan+1=2n,n∈N*,则数列{an}的通项公式为( )
| A. | an=($\sqrt{2}$)n-1 | B. | an=($\sqrt{2}$)n | ||
| C. | an=$\left\{\begin{array}{l}{(\sqrt{2})^{n},n为奇数}\\{(\sqrt{2})^{n-1},n为偶数}\end{array}\right.$ | D. | an=$\left\{\begin{array}{l}{(\sqrt{2})^{n-1},n为奇数}\\{(\sqrt{2})^{n},n为偶数}\end{array}\right.$ |
8.f(x),g(x)是定义在[a,b]上的连续函数,则“f(x)的最大值小于g(x)的最小值”是“f(x)<g(x)对一切x∈[a,b]成立”的( )
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| A. | 充分不必要条件 | B. | 必要不充分条件 | ||
| C. | 充要条件 | D. | 非充分非必要条件 |