Say we had a voltage source connected to a Low Pass RC filter and that this filter was connected to the negative node of an Operational Amplifier, so we would have a filter followed by an inverting amplifier topology.
Please keep in mind that I understand this circuit may be incorrect, I just built it as I had it pictured in my mind as the simplest way to illustrate my question.
In this case, how can I define the cutoff frequency of the filter, as well as the phase shift that the signal experiences? I know that the Low Pass filter delays the signal in 45º, and that the inverting OpAmp inverts the signal in 180º. Then, would the phase shift be -45º-180º=-225º?