@[blue_wine](/user/339966) $a$ 可以是 $0$，曲线包括一次函数
by EricWan @ 2023-07-22 14:09:58
等等，我是SB，$a<0$
by EricWan @ 2023-07-22 15:28:37
@[EricWan](/user/377873) 6
by blue_wine @ 2023-07-23 21:32:48
“曲线包括一次函数”
by ABCgfed @ 2023-08-24 16:31:48