Solve Op-amp Basic Problem: Output to Input Ratio

[Learnphysics]

Homework Statement

[PLAIN]http://img546.imageshack.us/img546/2389/opamp.png

Uploaded with ImageShack.us

All resistances are "R".

Find the output to input ratio for this Op-amp

Homework Equations

KCL, KVL, Voltage divider.

The Attempt at a Solution

I know no current flows into the Op amp through the inverting terminal so all the current flows into the feedback loop.

I know i can then use KVL and KCL to work out the current equivalencies such as:
KVL around the first loop in the feedbackloop:
(i1*R)-(i2*R) = 0
therefore: i1=i2.

KCL at the frst node in the Feedback loop gives:
i1+i2 = i3.

around the second node gives:
i3+i4 = i5.

KVL around the final loop in the feedback loop gives:
(i4*R) + (i5*R) = 0

But my main problem is trying to relate all this to the output voltage which i can't seem to get an expression for.

Please help

 

[berkeman]

Homework Statement

[PLAIN]http://img546.imageshack.us/img546/2389/opamp.png

Uploaded with ImageShack.us

All resistances are "R".

Find the output to input ratio for this Op-amp

Homework Equations

KCL, KVL, Voltage divider.

The Attempt at a Solution

I know no current flows into the Op amp through the inverting terminal so all the current flows into the feedback loop.

I know i can then use KVL and KCL to work out the current equivalencies such as:
KVL around the first loop in the feedbackloop:
(i1*R)-(i2*R) = 0
therefore: i1=i2.

KCL at the frst node in the Feedback loop gives:
i1+i2 = i3.

around the second node gives:
i3+i4 = i5.

KVL around the final loop in the feedback loop gives:
(i4*R) + (i5*R) = 0

But my main problem is trying to relate all this to the output voltage which i can't seem to get an expression for.

Please help

I would use the KCL equatinos for this problem -- they are more intuitive for me. Can you try it with KCL? What is the voltage at the "-" input terminal of the opamp?