$2 π f = \frac{1}{r c} = h$

$r = \frac{1}{\frac{1}{r 1} + \frac{1}{r 2} + \frac{1}{| x 1 |} + \frac{1}{| x 2 |} \dots}$

$h = \frac{1}{r c}$

$r c = \frac{1}{h}$

$c = \frac{1}{h r}$