(本栏目内容，在学生用书中以活页形式分册装订！)3已知等差数列an的公差为d(d0)，且a3a6a10a1332，若am8，则m为()A12 B8C6 D4解析：由等差中项性质可得a3a6a10a13324a8，故a88，则m8.答案：B4数列a，b，m，n和x，n，y，m均成等差数列，则2by2ax的值为()A正实数 B负实数C零 D不确定解析：由题意banm，yxmn，by(ax)(ba)(yx)nmmn0，byax.2by2ax.2by2ax0.答案：C5已知等差数列an、bn的公差分别为2和3，且bnN，则数列abn是()A等差数列且公差为5 B等差数列且公差为6C等差数列且公差为8 D等差数列且公差为9解析：依题意有abna1(bn1)22bna122b12(n1)3a126na12b18，故abn1abn6，即数列abn是等差数列且公差为6.故选B.答案：B.精品资料。欢迎使用。高考资源网w。w-w*k&s%5￥u高考资源网w。w-w*k&s%5￥u
