-φ''(x) ≧0 , a≦x≦b,
φ(a) ≧0
φ(b) ≧0
then φ(x) ≧0 , a≦x≦b
更新1:
-φ''(x) >= 0 , a =< x =< b, φ(a) >= 0 φ(b) >= 0 then φ(x) >= 0 , a =< x =< b
-φ''(x) >= 0 , a =< x =< b, φ(a) >= 0 φ(b) >= 0 then φ(x) >= 0 , a =< x =< b
收錄日期: 2021-04-23 17:47:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080320000051KK00081