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。

4. Market has two commodities A and B. The demand equations that relate the quantities demanded $x$ and $y$ to the unit prices $p$ and $q$ of the commodities A and B respectively are given by $x=f(p,q)=\dfrac{q}{p+q}$, $y=g(p,q)=e^{-(2q+p^2)}$. Are A and B substitute, complementary or neither? Answer : \underline{\quad(1)\quad}