Q.What are the formulae for estimating Marginal Cost and Marginal Product ?

Integration is the reverse process of differentiation, so the answer is option (c).

In the mathematical methods used in economics, differentiation finds the rate of change (the derivative) of a function, while integration does the opposite — it recovers the original function from its derivative and is used to find totals from marginal quantities. Because integration undoes what differentiation does, integration is called the reverse (inverse) process of differentiation.

…

Integration is the reverse process of differentiation.

Differentiation finds the rate of change (derivative) of a function, while integration is the opposite operation that recovers the original function from its derivative (the anti-derivative). This is why, in the mathematical methods used in economics, marginal quantities are obtained by differentiating total functions, and total quantities can be obtained back by in …

Integration is the reverse process of (a) differentiation.

Differentiation and integration are the two central operations of calculus and they are inverse to each other. Differentiation finds the rate of change (the derivative) of a function, while integration reverses this: given a derivative, integration recovers the original function (the anti-derivative). Because integration exactly undoes the effect of differentiation, it is called the reverse process of differentiation. In economics this is used, for example, to obtain a total function (like total cost) from a marginal function (marginal cost).

…