To find a maximum I want the second derivative to be negative.

最大值处的二阶导数是负数

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"It's bad optics to pay out at the maximum level when total shareholder return is negative, " Mr. Becker says.

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PostRocket also suggests how many posts a Page should post per day to get maximum reach and engagement without posting too much and causing negative feedback from fans.

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Using the data from 1913 through the end of 2011, the correlation between the maximum marginal income tax bracket and total Federal receipts is a negative 0.50.

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