I have to find the ratio of the lowest TM cutoff frequency to the lowest TE cutoff frequency.
The Attempt at a Solution
I have derived the general form of the cutoff frequency (which seems to be the same for both). I get the right answer if I take TE10 and TM11; but why is this? I know why you can't have TE00 or TM00, but why can't TM take TM10?