(adsbygoogle = window.adsbygoogle || []).push({}); f(x, y, z) ???

Hey there,

Sorry for the title, but i cannot find any appropriate one for it, here is my question!

If f(x, y, z) = tanh (x+2y+3z) => fx =?(what is the derivative of f(x, y, z) with respect to x?)

Actually, i know the answer but i do not get the idea! In case it might help, the answer is that: sech^2(x+2y+3z)

So, as i said, can someone explain it to me? How can they reach this answer? Thanks!

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# Homework Help: F(x, y, z) ?

**Physics Forums | Science Articles, Homework Help, Discussion**