Capacitive Reactance:

$$ X_C = \frac{1}{2 \pi f C} $$

Inductive Reactance:

$$ X_L = 2 \pi f L $$

LC Resonant Frequency: (Frequency where $X_C = X_L$)

$$ f_r = \frac{1}{2 \pi \sqrt{L C}} $$