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 …

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 …

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 …

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 …

Oct 29, 2020 · The function $ (x_1, x_2) \mapsto x_1$ is an affine function, and hence is concave (and convex). Summing two concave functions produces a concave function, and every …

Concave implies subadditive [duplicate] Ask Question Asked 12 years, 9 months ago Modified 3 years, 10 months ago

Oct 21, 2019 · A line is concave, but not strictly concave. Consequently, the graph of a concave function can include linear segments, but the graph of a strictly concave function cannot …

Real valued function $\neq$ extended real value function (the former is the setting setting of the question and my answer, the latter is your setting). In any case, your epigraph isn't even …

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?

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 …