I am kind of stuck in a question relating to phase velocity and group velocity.(adsbygoogle = window.adsbygoogle || []).push({});

I have been given that the index of refraction of a media is inversely propotional to the vacuum wavelength. And we are supposed to show the group velocity is half the phase velocity.

Now, the work I have done thus far is to have a relation between phase velocity and group velocity consisting of (dn/d{lambda}) where n is index of refraction. I don't know how to proceed from there..

Please guide me in the right direction.

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# Homework Help: Phase velocity and group velocity

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