Answer: straight lines that are parallel to each other
Explanation: Q: A jeweler can potentially use two inputs in her handcrafted jewelry: copper or bronze. She finds that when she minimizes her costs, she either uses copper or bronze but not both. What must her isoquants look like?
An isoquant curve is defined as a line of equal or constant economic production on a graph, chart or map which describes all the combinations of inputs that produce the same level of output. If the jeweler either uses copper or bronze but not both, it means that the copper and bronze are perfect substitutes, that is, they are two inputs that can be substituted for each other at a constant rate and at the same time maintaining the same output level. Her isoquants would appear as straight lines that are parallel to each other because all that matters is the sum of the two variables (copper and bronze), and not their individual values.