問題4

$$f(x,y,z) = \exp(x) \sin y$$ の時、$\mbox{grad} f$ を計算せよ

$$\mbox{grad} f = \left( \frac{\partial (\exp(x) \sin y) }{\partial x}, \frac{\partial (\exp(x) \sin y) }{\partial y}, 0 \right)$$ (41)

$$= \left( \exp(x) \sin y , \exp(x) \cos y, 0 \right)$$ (42)