# How to plot "$f(x,y) = x^2 + y^2$ on $(0,0) \times (1,1)$?

Hello Friends Thanks for your time.

Please help in plotting $f(x,y) = x^2 + y^2$ on a unit square with TikZ.

Thanks.

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Here is a very basic approach derived from an example in the pgfplots manual.

\documentclass{minimal}
\usepackage{pgfplots}

\begin{document}
\begin{tikzpicture}
\begin{axis}[colorbar]