Calculating work

[Banik_Housepian_2K]

Today we learned how to use the integral to calculate the work done under constant pressure.
I was wondering whether we can use integrals to calculate work if the pressure is not constant, and if so, how?

[Logan 3C]

That's part of the proof to getting the equation for an reversible, isothermal expansion on page 31 in the course reader. Its much more helpful to use the final equation though, at least in my opinion.

[Tina_Keshishian_2F]

I find the integral part of the equation a bit confusing, so I use the final equation also.

It's w=-nRT(ln(Vfinal/Vinitial))