Ok. I'm now studying economics and applied math, and I'm currently wanting to know what book or online resource could help me in learning how to model real life situations into functions. Most math and econ textbooks are garbage at this. I'll be more specific. In my study of Microeconomics, they introduce the concept of a production function. They just tell me that it is mostly a function of two variables, and the problems in the book already have the function given. No where do they teach (or give you problems) on how one can create their own production function given a specific situation. That's what I want to know. Most undergrad math book also suffer from this. Yes, there is simple function modeling with costs in some pre-cal books, but that is very easy and basic. My goal is to become better at modeling real life business, money, probability situations with functions. I'm working towards either doing computer programming, operation analyst, or actuarial work, and I want to become better at modeling. So which book (that is not too difficult, but not too easy) or online resource can help me? Thank you.