We want to integrate. So let's take the integral of both sides, going from the initial point to the final point.

分别从初态,到末态做积分，消去微分。

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Integration is not an algorithmic process like differentiation.

积分不是微分那种演算过程

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In other words, your job is to guess a function whose second derivative is a, and this is called integration, which is the opposite of differentiation, and integration is just guessing.

换言之,你的任务是要猜出一个二阶导数为a的函数,这就是积分,和微分恰恰相反,积分就是猜

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