for finding gain , just find voltage gain of the op amp first, which is say A. then find the K which is the feedback ratio from the feedback network. Gain is given by G= A/(1+KA).... the circuit is similar to colpitt with BJT.. just put the feedbacknetwork innegative feedback with the op-amp.
i need to analyise this circuit below
i need the equetion of the gain from feed back and for the amplifire
included the internal resistor of the operational amplifire(out put resistor )