What is the solution to this?

Question

The following figure shows the three-member CR phase shift chain:

Is there a frequency at which there is a 180 ° phase difference between the input voltage (U 0 ) and the output voltage (U 3 )?

If so, what is this frequency and what is the attenuation at this frequency?

Of course, I am not only interested in the end result, but in the overall derivation!

Update:

.

Answer 1

Did you forget "The following figure shows...". We can't see the figure. Hello?