題組內容

4. The terrain of a specific area is defined as \( h(x, y) = \begin{cases} 5 - \sqrt{x^2 + y^2} & , \text{if } \sqrt{x^2 + y^2} < 5 \\ 0 & , \text{otherwise} \end{cases} \)

(c) Determine the unit normal vector to the land surface at point A. (10%) (10%)