I take a look at the second derivative, which is the second order condition.

我需要求出二阶导数,即需要寻找二阶条件

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I actually need to check the second order condition.

实际上我们还需要验证二阶条件

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And the mathematics of that equation involved a double derivative in time of x 0 plus some constant times x equals zero with some constraints on it.

那个数学方程式,包括了x对时间的二阶导数,加上常数乘以x等于,还有一些限制条件。

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So how do I check the second order condition?

怎样验证二阶条件呢

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