They made it clear to the former Nigerian military ruler that a return to constitutional order is a pre-condition for direct talks with President Mamadou Tandja.

VOA: standard.2009.11.14

Okay, good, so what we're going to do is we're going to differentiate this thing to find a first order condition.

好吧,那我们接下来,对它求导后找出一阶条件

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So if we differentiate this object, I'm gonna find a first order condition in a second.

想要求它的导数,先让我想想一阶条件

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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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This was a first order condition or a first order necessary condition.

这个只是一阶条件,是必要条件

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So here it is, I've got my first order condition.

到这里我满足了一阶条件

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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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So how do I check the second order condition?

怎样验证二阶条件呢

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To make this a first order condition, I'm going to say "at the best response," put a hat over the 1.

为了达到一阶条件,我说在最佳对策下,在S1上写个帽

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It tells me that the best response to S2 is the ?1 that solves this equation, that solves this first order condition.

我们得出S2的最佳对策是?1,?1是这个方程的解,它满足一阶条件

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I differentiate a second time and check the sign, so the second order condition, I differentiate this expression again with respect to q1.

我们对它进行二次求导然后看符号,这个式子的二阶导数,就是一阶导数再对q1进行求导

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