when do you use derivatives in economics?

Question

do you use them when trying to find elasticities, indifference curves, or what? when do you need to find the derivative?

Answer 1

Elasticities are derivatives.

You take them any time you want to find out the sensitivity of some variable to its inputs.

You also need to take derivatives any time you ar emaximizing or minimizing some variable. For example, to maximize profit as a function of price, you take the derivative of the profit function with respect to price and solve for zero.

Answer 2

you can also use them to calculate marginal revenue, marginal profit, actual profit among other things