[積分應用]

[lukechen90 (...?)]

1.show that f'''(x)>0 on an interval, then f is concave upward on that
  interval.

2.show that -1/2<x/(1+x^2)<1/2 for every value of x
                =         =

這兩題不知道從哪裡切入算會比較好Q_Q
麻煩高手幫解答~~

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※ 編輯: lukechen90      來自: 218.171.163.55       (05/11 13:59)
※ 編輯: lukechen90      來自: 218.171.163.55       (05/11 14:00)
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