"It was the Islamic world that paved the way for much of the technology and science that we now take for granted.
VOA: standard.2009.11.03
This is going to be probably a homework at some point to do this. For now, let's take it for granted. Let's take it for granted that we know how to calculate this derivative from an equation of state like this.
We just take it for granted that what we're reading is completely within our own horizon and we don't make any effort at all to understand that which is fundamentally or at least in some ways different.