简单的高数题:将下列周期为2π的函数展开为正弦级数或余弦级数
如题所述
第1个回答 2017-06-15
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追问bn由倒数第二部到结果怎么算?
an为什么是0?
追答..那是傅立叶级数的标准型呀……
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/4610b912c8fcc3ce2f7a28719845d688d43f203e?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
凡是解出了的bn an都必须往那个标准式里代
追问我是说算bn时由倒数第二部到bn的结果怎么算?
追答望采纳哦
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/48540923dd54564e564a047bb9de9c82d1584f41?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
追问帮我解释完就采纳
追答...就是展开重找规律 使结果看起来好看💩
其实这一步不是必须的,只是职业病而已……
追问然后怎么算?写一下详细过程,怎么找规律
奇偶得数带入不是结果啊?
奇是4/nπ,偶是0?
追答![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/cefc1e178a82b901553a2c71798da9773812efd9?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
哦 那我那种是错的 😅
抱歉抱歉 你就不要采纳了
就是把cos(npi)换掉就可以