Under what condition is a consumer's optimal point of consumption determined?

The optimal point of consumption for a consumer is determined when indifference curves and the budget constraint touch. This point represents the highest level of utility a consumer can achieve given their budget limitations and the prices of goods. Indifference curves illustrate different combinations of goods that provide the same level of satisfaction to the consumer. The budget constraint, on the other hand, shows the combinations of goods that the consumer can afford based on their income and the prices of those goods.

At the point where the indifference curve tangentially touches the budget constraint, the slope of the indifference curve (representing the marginal rate of substitution between two goods) equals the slope of the budget line (representing the ratio of the prices of the two goods). This condition signifies that the consumer has maximized their utility because they cannot achieve a higher level of satisfaction without exceeding their budget. Thus, this optimal consumption point reflects the most efficient allocation of the consumer's resources given their preferences and constraints.