4 Elementary functions

In this chapter we first discuss the concept of function and further summarize the properties of several known types of real functions of a real variable $f$.

4.1 What is it a function?

4.2 The absolute value

4.3 Lower and upper integer part

4.4 Linear function

4.5 Quadratic function

4.6 Polynomial function

4.7 Roots

4.8 Rational function

4.9 Trigonometric functions

4.10 Exponantiation and logarithm

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