I'm supposed to be analysing this circuit to go with my lab report. However I haven't seen a circuit like this. First off I'm not sure what the symbol is on the top left resistor (15kΩ//1.2kΩ) means. Secondly I'm used to doing inverting op amps and they generally don't have many/ any resistors attached to the side that doesn't have the voltage source. I'm curcious if and what effect the other resistors will have. I'm assuming there's some kind of feedback there, however I'm not sure how to connect the voltage source and the feedback. Any help would be greatly appreciated. The circuit diagram is below.