並列共振回路のエネルギー収支

$\displaystyle I$	$\textstyle =$	$\displaystyle i_R + \frac{{dq}}{{dt}} + i_L$	(53)
$\displaystyle v$	$\textstyle =$	$\displaystyle i_R R = \frac{q}{C} = L\frac{{di_L }}{{dt}}　回路方程式$	(54)
$\displaystyle vI$	$\textstyle =$	$\displaystyle i_R ^2 R + \frac{q}{C}\frac{{dq}}{{dt}} + Li_L \frac{{di_L }}{{dt}}$	(55)
$\displaystyle vI$	$\textstyle =$	$\displaystyle i_R ^2 R + \frac{d}{{dt}}\left( {\frac{{q^2 }}{{2C}} + \frac{1}{2}Li_L ^2 } \right)$	(56)