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## Homework Statement

An object is placed

**12.8 cm**to the left of a

**diverging lens of focal length -6.35**cm. A converging lens of

**focal length 12.8 cm**is placed a distance of d to the right of the diverging lens. Find the distance d that places the final image at infinity

## Homework Equations

1/f=1/di+1/do

## The Attempt at a Solution

I understand that I have a few unknowns and need to solve this a couple of times to discover the di:

So [/B]1/f=1/di +1/do : MAIN EQUATION

Di: 1/(-6.635)=1/di+1/(12.8cm). gives me di of -4.244 cm

Do2: 4.244+25.6=29.844 cm

1/do2+1/di2=1/f2 (1/2984)+1/di2=1/12.8cm

Eventually I end up with -22.41 cm.

I don't know if I am supposed to solve this for 2nd time through lens. Therefore, I thought I ended up -22.41 cm. However, that is not right. Please help.

**I have a small request: Please read the problem very carefully. I do not want to answer what kind of mirror this is if the problem already answers it. I have had to answer questions regarding variables that I clearly explained in the problem. Please refrain from it. I want to learn so if you ask me a question to help me better understand the problem than that is fine. BUT DO NOT ASK ME ABOUT WHAT THE VARIABLES ARE BECAUSE I FEEL LIKE I AM REPEATING MYSELF RATHER THAN LEARNING ANYTHING NEW.**