"Water depth is $x$. Water volume in vassel is calculated by
${V}\left(x\right)=\frac{\pi}{3}\left(30x^2-x^3\right)$ while $0 \leq x \leq 30$
While functions $V(x)$ alteration converting to differential, value what maximum deviancy may be done while calculating water volume, if it's depth was measured at 1mm precision."
Do I need to count remanant member here? (well... $Rn\left(x\right)=f\left(x\right)-Pn\left(x\right)$?)