I first found the transfer function, which is the impedance of the vertical branch divided by the series sum of the impedances.

After, I took the limit of the transfer function of this LC low pass filter at low and high ##/omega##.

I then found the corner frequency by setting ##H_(low)$$ and ##H_(high)## equal to each other.

Next, I take the magnitude of the transfer function, but the expression I get for it causes the denominator be zero, which is bad. Ideally, at the corner frequency, I should get ##\frac{1}{sqrt(2)}##