→ j401f2:結論的部分需要嚴謹一些 大家考試時不要忘記 11/19 11:54
推 fbird:有下有推！ 11/19 12:41
→ fbird:結果沒考阿!!!!!>"< 11/19 21:10
推 j401f2:你連這題都不會阿!?!?我用膝蓋想就知道了!!y 11/20 22:21
老師要我們證明的其中一題
Theorem："Extreme point of a convex set are those that do not lie within the
line segment between any two other point of the set"
Proof Here：
Let X isn't a extreme point belongs to S'(a convex set)
According to convexity,
Let X1&X2 belong to S'
then X=λX1+(1-λ)X2 , 0≦λ≦1 (X、X1、X2 belong to S')
If λ=0, then X=X2
If λ=1, then X=X1
Because that X1&X2 are selected randomly,
so X1 or X2 may be a extreme point
So X may be a extreme point, too;
which is contradict that X isn't a extreme point.
深夜中想出這一題 希望可以造福大家...
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