1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Thin lens equation

  1. Aug 8, 2006 #1
    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 similiar 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.
  2. jcsd
  3. Aug 8, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    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
  4. Aug 8, 2006 #3


    User Avatar

    Staff: Mentor

    Now how in the heck did you know that? No wonder you're the GURU! :biggrin:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook