来自冯新宇的问题
数列和满足…(n=1,2,3…),求证为等差数列的充要条件是为等差数列.____
数列和满足…(n=1,2,3…),求证为等差数列的充要条件是为等差数列.
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2019-06-26 05:25
数列和满足…(n=1,2,3…),求证为等差数列的充要条件是为等差数列.____
数列和满足…(n=1,2,3…),求证为等差数列的充要条件是为等差数列.
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【分析】先证必要性:若{bn}为等差数列,设首项b1,公差d,由题意能导出,{an}为是公差为的等差数列.再证充分性若{an}为等差数列,设首项a1,公差d,则能导出bn+1-bn=2d,即{bn}是公差为等差数列.证明:必要性:若...