Finding output voltage of op amp differentiator with three resistors

[FBS]

Homework Statement

(See attached figure) I need to find V0 in terms of R1, R2, R3 and C.

Homework Equations

V0 = -RC (dVs/dt) for a differentiator

The Attempt at a Solution

I understand I have to apply KCL at the node between C and R1, and I've also determined that R1 and R2 are in series (not sure) but I don't know what to do with R3.

{C * (d(Vn - Vs)/dt)} + {(Vn - V0)/(R1 + R2)}

 

[crixus]

Hey Did u notice that the node between C and R1 is a virtual ground.

 

[rude man]

Hey Did u notice that the node between C and R1 is a virtual ground.

Plus you're missing one node, plus your equation is incorrect I'm afraid.

Just write the KVL for every node correctly & it'll be obvious what to do with R3 ...