To find the -3dB corner frequency of the circuit, start by writing the output voltage equation as a function of frequency. The -3dB point corresponds to a reduction in output voltage to a specific ratio, defined by 3dB = 20 Log10(X). The circuit's initial voltage divider already reduces the voltage by more than 3dB, indicating that the focus may be on the frequency where the output is 3dB down from a DC input. Understanding these relationships will guide the analysis of the circuit's frequency response.