Answer
x-axis: pressure $p$ in $lb/ in ^2$,
y-axis: the gas as a function of its volume $f(v)$ in $in^3$.
Work Step by Step
The function notation is given by $p = f(v)$.
We want to sketch the development of the gas as a function of its volume $f(v)$ related to the pressure $p$.
Therefore, x-axis represents the pressure $p$ in $lb/ in ^2$ (pounds per square inch) and the y-axis represents the gas $f(v)$ in $in^3$ (cubic inches).