Hello Lisa,
I use Unitrode App-Note U-165 (1999) (SLUA86) to design a CCM-Flyback.
As far as I can verify the formula (26) on page 12 seams not to be correct (I think Rout should be placed in the numerator).
I checked for newer documents on the TI-Homepage and found SLUA96 (dated 2003).
By checking formula (26) I still believe there is an error.
Comparing the units: (V*V*V/A) / (V*V*V*V*s/A) =1/(V*s) ??
So I would expect to get 1/s for frequency.
Best regards
FrankM