I am having some trouble with this one...any help would be appreciated.(adsbygoogle = window.adsbygoogle || []).push({});

A 31.8cm focal length converging lens is 21.6cm behind a diverging lens. Parallell light strikes the diverging lens. After passing through the converging lens, the light is again parallel. What is the focal length of the diverging lens.

I used the lens equation to find the distance of the image and got 12.86cm, then plugged that in to the lens equation for a diverging lens and got -8.061 cm. However, that answer is incorrect. Any help would be appreciated.

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# Homework Help: Lens (optics problem)

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