那么我们来讲凸函数（convex function）为什么叫做是凸（convex）的： 这是因为凸函数与凸集（convex set）有联系，而凸集的定义没有争议。 1. 凸函数与凸集通过 sublevel sets 这个概念 …

Jun 24, 2019 · 图像以上为 凸集 的就是凸函数，如开口向上的二次函数，英文里叫Convex或concave up，反过来就是凹函数，英文叫Concave或concave down，这是国际上的定义。 国内 …

英文世界中，一般分为Convex Function和Concave Function 通常意义上，前面是向下凹，后面是向上凹。 一个 助记 是con后面跟的是V，形状就和V类似。 否则，则形状就是倒着的 Λ 而国 …

Convex function Quasiconvex function Pseudoconvex function 在R上考虑就很容易理解。在凸要求不高过xy连线的地方，拟凸只要求不高过xy中较大者，所以凸蕴含拟凸；而伪凸则要求，“ …

Nov 26, 2018 · I have now corrected the errors in my question (mixed up strictly concave and concave) and broadly ask about when I can use the second derivative to prove concavity (as …

Nov 1, 2017 · What's the intuitive difference between quasi-concavity and concavity? Can you give an example of a quasi-concave function that is not concave?

Concave implies subadditive [duplicate] Ask Question Asked 12 years, 10 months ago Modified 3 years, 11 months ago

If you know the standard English meaning of the words convex and concave, you can remember that for a convex function it is the epigraph that is convex, and for a concave function it is the …

May 7, 2015 · What ways are there to prove that a function with more than 2 variable is concave?ٍ I know we can check that the associated Hessian matrix is negative (semi) …

Mar 27, 2015 · The function $g (x)$ is a concave. You can see from your graph that the line passing through two given points on the curve lies below the graph of $g$, not above the …