Optimization Within the Context of Differential Calculus

- What are some of real life fields in which the concept of optimization could be applied? Mention at least two, in general, and explain how the concept is applied (please, avoid specific copy pasted information about a detailed application. Instead, read and write understandable well sumarized paragraphs).

(EXPLAIN IN YOUR OWN WORS AS DETAILED AS POSSIBLE - NO COPY PASTE)

Include citations if used