given:[tex](adsbygoogle = window.adsbygoogle || []).push({});

f(r)=x ^{2}+3y ^{2} +2z ^{2} [/tex]

The task was to calculate at the point (2,3,1): the grad of f, tangent plane, directional derivative in the direction (2,-1,0) but also to find the maximum value of f subject to the condition that.

[tex] r ^{2} =1[/tex]

I've done all except the last part, I have no idea what I am supposed to do here, and I don't really understand what they want.

Please explain.

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# Maximum value of f(r)

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