Rational Functions

All of these "rational" function have asymptotes. They are rational because they know not to reach certain places. 

A rational function is any function which can be defined by a rational fraction. For example, an algebraic fraction such that both the numerator and the denominator are polynomials. The coefficients of the polynomials do not need to be rational numbers, they may be taken in any field K.

The asymptotes are represented into dotted lines. The curved lines would be the functions. Note, the functions are not tangent to the asymptotes but are very close as it reach the end.

Joke of the week: 

The mathematician worked at home because he only functioned in his domain.