コンデンサーと抵抗

$\displaystyle V_0$	$\textstyle =$	$\displaystyle \frac{q}{C} + i R$	(25)
$\displaystyle V_0 i$	$\textstyle =$	$\displaystyle \frac{q}{C}\frac{{dq}}{{dt}} + i^2 R$	(26)
$\displaystyle V_0 i$	$\textstyle =$	$\displaystyle \frac{d}{{dt}}\left( {\frac{{q^2 }}{{2C}}} \right) + i^2 R$	(27)