filter - Calculating Fc (cutoff) of series to RC to ground on inverting input of non-inverting amplifier - Electrical Engineering Stack Exchange
Inverting and Non Inverting Summing Amplifier | Voltage Adder
Inverting Gain for ideal and non-ideal Op-Amp Calculator | Online Inverting Gain for ideal and non-ideal Op-Amp Calculator App/Software Converter – CalcTown