Which of the following expressions gives the work done by an ideal gas when it undergoes a reversible isothermal change from an initial volume Vi to a final volume Vf at temperature T? (Symbols have their usual meaning.)
a) W=−nRTln(ViVf)
b) W=nRTlnViVf
c) W=nRT(ViVf−Vi)
d) W=21nR(Vf2−Vi2)