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\textbf{Partial Differentiation}

\textit{\textbf{Functions of more than one variable}}
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\textbf{Question}

Sketch the graph of the function.

$$ f(x,y)=0, \ \ \ (0\le x \le 2,\ 0\le y \le 3)$$


\textbf{Answer}

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\epsfig{file=PD-1A-1.eps, width=50mm}
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