1. The problem statement, all variables and given/known data Please, I would like to know how to find the factor by which the capacitance is multiplied A picture of the Op Amp is here: http://en.wikipedia.org/wiki/File:Cap-mult-op.svg Zc is complex impedance of C 2. Relevant equations none given 3. The attempt at a solution choose, I2 through R2 left to right I1 through R1 top to bottom so Iin = I1+I2 = (Vin-Vout)/R2 + Vin/R1 +Zc Vout =V- = V+ = (ZcVin)/(R2+Zc) ... Iin=Vin((R2+R1)/(R1(R2+Zc))) And then I'm not sure how to calculate the effective capacitance. I think it is supposed to be increased by a factor of R2/R1 but I dont know how to get that.