定义

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/659d2573-8f3c-491a-bfc6-b3f0c373e106/Untitled.png

如何找拐点

  1. 利用必要条件找点：$f''(x)=0$ 或不存在
  2. 利用充分条件判定点：第一判别法、第二判别法

https://keyon-photo-1256901694.cos.ap-beijing.myqcloud.com/markdown/20200322144336.png

https://keyon-photo-1256901694.cos.ap-beijing.myqcloud.com/markdown/20200322144344.png

例题

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/f47c3717-c145-43ac-b587-c62e833e0268/Untitled.png

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/e6e8e91e-3e8f-417a-b8f9-0ea292772943/Untitled.png

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/8cc2748f-d8f1-4816-ba3f-15049d2faec6/Untitled.png