Why Do I Get a Negative Value for R2 in My Voltage Divider Circuit?

[Matt1234]

Homework Statement

Hello, can someone please help me create the following curcuit? Id like to know the steps so i can to solve this. I don't seem to be getting the correct answer its very frustrating because it seems so simple. please advise.

[PLAIN]http://img517.imageshack.us/img517/8919/54967623.jpg

Homework Equations

KVL
KCL
Ohms Law

The Attempt at a Solution

Notice i keep getting a negative R2:
Please advise

[PLAIN]http://img404.imageshack.us/img404/5573/lastscanq.jpg

 

[Matt1234]

After some more review, R1 must be 2 times greater then Req in order to get that drop arrcoss the load. Req being the equivalent resistance of R2 and 1000 ohms.

Now the current being close to 5ma is the next step.

 

[Matt1234]

anyone please?

 

[gneill]

Suppose you were to replace the 15V supply and R1 and R2 with a Thevenin equivalent. Then you'd have a supply in series with a single resistor.

Now consider the output voltage with 0mA and 5mA loads. If you set them to your +/- 10% conditions, you should have two equations in two unknowns, they being R1 and R2...