concave function

(redirected from Concave downward)

concave function

[′kän‚kāv ′fəŋk·shən]
(mathematics)
A function f (x) is said to be concave over the interval a,b if for any three points x1, x2, x3 such that a <>x1<>x2<>x3<>b, f (x2)≥ L (x2), where L (x) is the equation of the straight line passing through the points [x1, f (x1)] and [x3, f (x3)].
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References in periodicals archive ?
The curve starts slowly and then rises more steeply until finally an inflection point is reached after which it becomes concave downward.
The experiment found that, though the group exposed to varying quantities of light did have relative spikes in pressure output, it graphically spiked initially and rotated between concave upward and concave downward with respective exposure to light and to no light.
The shape of this curve for total emissions, concave downward, is typical of all charges.
However, they show different curvatures: the loading curve is concave downward as it lies below its tangent lines at any point, while the unloading curve is concave upward as it lies above all its tangents.
This results in a concave downward curve of the model prediction for the unloading branch, which is the opposite to that of the experimental observation.