Solve Thin Lens Equation: Diverging Lens, Virtual Image

[spoonthrower]

I am stuck on this problem because it been like 6 yrs since i took geometry and its due by 9 am. please help!

Derive the thin lens equation:

1/object distance + 1/ image distance = 1/focal length

for a divergent lens, using a diagram of a divergent lens (hint: use similar triangles)

I have no idea where or how to start. please show me how to do it. I know the focal length for a diverging lens is always negative and always produces a virtual image.

 

[Astronuc]

I am stuck on this problem because it been like 6 yrs since i took geometry and its due by 9 am. please help!

Please ask well before the HW deadline, which was due in 5 hrs and 13 min at time of OP.

For future reference - http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/lenseq.html

 

[berkeman]

Please ask well before the HW deadline, which was due in 5 hrs and 13 min at time of OP.[/url]

Now how in the heck did you know that? No wonder you're the GURU!