"How are you, Peter?"

Translation: Te hogy vagy, Péter?

[Alsweetex]

The "Te" isn't necessary here right?

[cathddu]

it isn't, usually you would only include 'te' if you wanted to emphasise the object, for example in the following conversation:
-Hogy vagy, Kati? (How are you Kate?)
-Jól, köszönöm. (Fine, thanks.)
-És te hogy vagy, Péter? (And how are YOU, Peter?)

[GalvanTivadar]

You are perfectly right.

[linguafiqari]

No, you can drop it :)

[GalvanTivadar]

No, the two sentences are not really equal, I would translate "Te hogy vagy, Péter?" such as "As for you, Péter, how are you?".

[androghost]

What is Te here standing for ?

[eshragis]

"Te" is the familiar form of "you". It is not necessary here, since it is understood.

[GrubbaFong]

So, it is not necessary here, but to get the question correct, we must include it, remembering of course that we have never seen this word up to this point.