Question

一道数学题，关于拉格朗日中值定理的，谢谢解答~~最好英文，中文也可以~

Suppose that f(x) has second derivative in (a,b),and f(x1)=f(x2)=f(x3)where a<x1<x2<x3<b,Prove:there is at least one point t in (x1,x3)such that f''(t)=0
注：结尾为f(t)的二阶导数，可能有点看不清

Answer 1

罗尔中值定理就可以证明了。

Answer 2

222