已知数列{a n },构造一个新数列a 1 ,(a 2 -a 1 ),(a 3 -a 2 ),…,(a n -a n-1 ),…,此数列是首1,公比为 1 3 的等比数列. (1)求数列{a n }的通项; (2)求数列{a n }的前n项和S n .
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
皮皮学刷刷变学霸
举一反三
【单选题】If demand reversal is the explanation of the Leontief paradox, this would imply that the demand by the United States for labor-intensive goods is relatively ( ) and therefore that US wages would be re...
【简答题】Draft No.20060613 Amount: HKD32,150.00 Place and date of draft: Tianjin,8 May,2006 Paying bank: Bank of China,Hong Kong Payee: United Trading Company, Hong Kong Pay against this draft to the debit of ...
【单选题】With which of the following offences would a person be charged if they interfered with the usual process of share prices moving up and down in accordance with supply and demand? A Insider dealing B ...
【判断题】According to J. S. Mill, if we know the domestic demand expressed by both trading partners for both products, the equilibrium terms of trade can be defined.
【简答题】翻译句子 The basic transaction process of e-commerce Preparatory stage Online research before trading Market demand survey English questionnaire design
【单选题】The reduction of brokerage commissions for trading common stocks that occurred in 1975 caused the demand for bonds to ________ and the demand curve to shift to the ________.