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\textbf{Partial Differentiation}

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

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\begin{description}
\item{(a)}
Is the landscape steepest at point P or R?

How can you tell?

\item{(b)}
Describe the topography of the region around Q.

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\textbf{Answer}

\begin{description}
\item{(a)}
The landscape is steepest at $R$. This is because at this point, the
level curves are closer together.

\item{(b)}
Q is a ``pass'' between the two peaks to the east and to the west. The
land is level at Q, but rises as you move east/west and falls as you
move north/south.

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