The Art of Mathematics

Help 6.19

ceil — ceiling function

1. Definition

Ceiling is the nearest integer to the righ — the smallest integer greater than or equal to the argument.

2. Graph

The ceiling function is defined everywhere on the real axis — so its domain is (−∞, +∞). Its stair-like graph is depicted below — fig. 1.

Fig. 1. Graph y = ceil x. Fig. 1. Graph of the ceiling function y = ceilx.

The function codomain is the set of integer numbers.

3. How to use

To calculate the ceiling of the number:


To get the ceiling of the complex number:


To get the ceiling of the current result:


To get the ceiling of the number z in calculator memory:


4. Support

The ceiling function of the complex argument is supported in the professional version of the Librow calculator.