曲线<img src="https://static.zxtiku.com/wangke/imgs/topic/3ca2dd06592f9f9402a398aa14d9609b.jpg"/>的凹区间为<img src="https://static.zxtiku.com/wangke/imgs/topic/5702d830a63843766a8d10622693b693.jpg"/>，凸区间为<img src="https://static.zxtiku.com/wangke/imgs/topic/1a70137f2994a0f91afe5c5434d9f7d1.jpg"/>，拐点为<img src="https://static.zxtiku.com/wangke/imgs/topic/c47b928e019ff18ff176f951f4641dbf.jpg"/>.