Mathematical economics
Appearance
The Mathematics and Economics are totally linked, One uses Differentiation and Integration to find the Elasticities of Demand and Supply.
Following are few Examples:
If the total cost of the firm is given by TC(x) = x3 + 5x + 6 and the target is find the Marginal Cost.
Then use derivative of C with respect to x i.e. d(TC)/dx = 3x2 + 5.