- #26

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OK. I was reading the exact wording the OP posted in #14 instead of his confused statement in the original post.The OP wrote ##z \leq x^2+y^2+x^2##, so

[tex] x^2+y^2+z^2-z \geq 0 \Longrightarrow x^2+y^2 + (z - 1/2)^2

\geq 1/4.[/tex]

I did have my morning coffee, but it was de-caff.