Final answer:
The law of diminishing marginal utility implies that indifference curves are convex with respect to the origin, reflecting the principle that consumers experience a decreasing satisfaction with each additional unit of a good consumed.
Step-by-step explanation:
The law of diminishing marginal utility implies that indifference curves are convex to the origin. This shape is due to the diminishing marginal utility, which means that as a consumer consumes more of one good, the additional satisfaction obtained from consuming each additional unit declines.
Thus, to maintain the same level of overall utility, and assuming the utility function is smooth and continuous, the consumer would need to give up fewer units of one good to gain an additional unit of another good as they move down the curve. This is why indifference curves are steeper on the left and flatter on the right and why they bow in towards the origin, demonstrating the trade-off between two goods at differing rates of substitution, known as the marginal rate of substitution.