Choose all correct sentences

a. The power (equation 8) is maximum when the value of the impedance is greater than the value of the resistance.
b. Resonance occurs when omega squared space equals 1 divided by space L C
c. At resonance, the power is maximum and the impedance is minimum.
d. At resonance, R squared space equals space (X subscript L minus X subscript c )squared
e. The quality factor Q space equals space fraction numerator square root of L C end root over denominator R end fraction
f. The quality factor Q space equals space fraction numerator square root of L divided by C end root over denominator R end fraction