\begin{eqnarray}
dV = V_r(r_0, h_0)dr + V_h(r_0, h_0)dh\\
= (2\pi rh)_{(1,5)}dr + (\pi r^2)_{(1,5)}dh\\
= 2\pi (1)(5) dr +\pi dh\\
= 10\pi dr + \pi dh
\end{eqnarray}



result in


dV = Vr (r0 , h0 )dr + Vh (r0 , h0 )dh (2)
   = (2πrh)(1,5) dr + (πr2 )(1,5) dh   (3)
               = 2π(1)(5)dr + πdh      (4)
                    = 10πdr + πdh      (5)