then the answer looks like this.

那么这就是答案
If you knew the second derivative of x,

如果你知道x的二阶导数
the answer looks like that.

那么答案就是上面那个
Now, we have to ask what are these numbers, b and c.

我们来看看b和c代表的是什么
So let me go back now to this expression,

让我们再回到这个式子
It is true mathematically, you can add two numbers,

在数学上它是正确的你可以引入这两个常数
but you've got to ask yourself,"What am I doing as a physicist

但是你需要问问自己当我引入这两个常数时
when I add these two numbers?"

这么做有什么物理意义
What am I supposed to do with a and b?

我将怎么处理这a和b两个常数
I mean, with the b and c? What value should I pick?

我指的是b和c 这两个系数应该取什么值
The answer is that

答案是这样的
simply knowing the particle has an acceleration

仅仅知道质点的加速度