But, of course, it's going to come from the fact that these second derivatives are also equal.

但是，结果同样是依赖于,二阶混合偏导数相等。

麻省理工公开课 - 热力学与动力学课程节选

Because these mixed second derivatives are the same thing.

因为这两个混合二阶偏导数,是相等的。

麻省理工公开课 - 热力学与动力学课程节选

Now let's take it in the other order.

我们用另一种顺序求二阶偏导数。

麻省理工公开课 - 热力学与动力学课程节选

So, using those, now, what happens if we take the second derivative of A, the mixed derivative, partial with respect to T and the partial with respect to V.

如果我取A的二阶导数,混合导数，对T偏微分,再对V偏微分。

麻省理工公开课 - 热力学与动力学课程节选

dA/dT dS/dV So this is negative dS/dV.

是负S，It’s，negative，S。,这个二阶偏导数是负的恒定温度下的。

麻省理工公开课 - 热力学与动力学课程节选