推 suhorng :反曲點定義：曲線在該點兩端凹口方向相異 10/25 21:02
→ suhorng :g''(0)不存在：直接從定義去算會發現極限不存在 10/25 21:04
題目是
Show that the function g(x)= x｜x｜ has an inflection point at (0﹒0)
but g"(0) does not exist.
是用微分去比較嗎? 寫不太出來...
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 114.45.46.137