Here we have two standard functions, the constant and the function , and thus:
1. Basisboek Wiskunde.
by: Jan van de Craats en Rob Bosch (2nd ed) (in Dutch)
A much recommended book often found less suitable for self-study.
2. Essential Mathematics for Econonomics and Business.
by: Bradley and Patton (4th ed).
Being used a.o. at Erasmus University Rotterdam.
3. Essential Mathematics for Economic Analysis
by: Sydsaeter and Hammond (4th ed).
A thorough book used at a.o. Erasmus University Rotterdam.
4. Calculus: Concepts and Contexts.
by: Stewart (2nd ed).
Detailed coverage of many topics of calculus.