The Basics
- Simple definition: A branch of mathematics dealing with accumulation, areas under curves, and summing infinitesimal quantities.
- Core idea: Finding total amounts from rates of change.
- Think of it as: Reconstructing the whole journey from knowing the speed at each moment.
What It Actually Means
In economics, integral calculus is used to calculate total quantities from marginal functions. If marginal cost tells you the cost of producing one more unit, integrating marginal cost gives total cost. Similarly, consumer surplus is the area under the demand curve above price – found through integration. It’s the inverse of differentiation.
Example
If a firm’s marginal revenue is known, integrating it over the quantity sold gives total revenue. This helps in profit maximization and understanding how changes in output affect overall revenue.
Why It Matters
Calculus is the language of optimization in economics. Understanding integrals helps grasp concepts like consumer and producer surplus, total cost and revenue, and present value of future income streams.
Don’t Confuse With
Differentiation – differentiation finds rates of change; integration finds total accumulation. They are inverse operations.
See also
Differentiation • Marginal Analysis • Consumer Surplus • Producer Surplus • Present Value
Read more about this with MASEconomics: