Problem #$4$: $(10)$

The heat capacity $($CP$)$ of methane, defined as the amount of heat required to raise the temperature of a unit mass of $C{H}_4$ by one degree at constant pressure, is over a limited range of temperatures given by the expression:

$Cp=34\mathrm{.}31+5\mathrm{.}469{10}^{-2}Tc+0\mathrm{.}3661{10}^{-5}T{c}^2-11\mathrm{.}00{10}^{-9}T{c}^3$

where $T$ is in $C.$ The expression of $Cp$ is in