Definition of quality factor as function of frequency
You're using a definition from wikipedia which explicitly has failed verification:


  


Obviously, tread carefully if you use wikipedia, and twice so if the authors of the wikipedia page disagree on something.
Generally, the quality of wikipedia on fundamental EE is often not very good. Do not use Wikipedia as only source! (that goes for anything, basically, but it really applies to wikipedia, and students these days are taught that wikipedia is of mixed quality.)

So, I'd not pay any attention to that definition unless it's especially useful to me. I'm too lazy to check whether that formula actually is correct (i.e. means the same as the usual definitions of quality factor).

Instead, use the much more common formula that relates the losses to the energy oscillating in and out of an inductor (that we model with a series parasitic resistance):

$$Q_L(f) =\frac{X(f)}{R} = \frac{2\pi f L}{R}$$

with \$f\$ being the frequency, \$L\$ the inductance at that frequency (that's not a constant in real materials) and \$R\$ representing ohmic losses.