Problem

甲、填充題：共 8 題，每題 8 分，共 64 分。請在答案卷上列出題號依序作答。

5. Find the direction in which the function $f(x,y)=x^2y+e^{xy}\sin y$ increases most rapidly at the point $(1,0)$. Answer : \underline{\quad(1)\quad}