Find Thevenin Equivalent Resistance for Network

[qwerty2x]

Homework Statement

Find the Thevenin Equivalent resistance for the network below:
http://img27.imageshack.us/img27/8508/circuit.png [Broken]

Homework Equations

R=(1/R1+1/R2)^-1

The Attempt at a Solution

Hi all,

to find the resistance i short circuited the volage sources and created an open loop across the current source. Then it looks like the current will not travel through the uppr loop beacuse its in parallel with a short circuit(where the current will rather go). I concluded that by breaking the circuit at Vo we have R1 and R2 in parallel. Which leaves us with the resistance being 2.7K ohm. but that's incorrect according to my book.

Help appreciated thnks

 

[G01]

You removed the sources in the correct way, but I'll need to see your calculations if I am going to be able to see your mistake. Can you show your calculations? Also, what do you mean by R_1 and R_2? There are five resistors, not just two.

 

[qwerty2x]

thanks for the reply,

resistance=((1/8.3k)+(1/4.1k))^-1 (just 2 resistors in parallel)
so resistance is 2.74kOhms

 

[Redbelly98]

The 2 resistors in the top half of the circuit are not in parallel (after removing the current source and shorting the voltage sources).

Note, the resistance is to be calculated across the + and - terminals of Vo.