The Art of Mathematics

Help 6.19

ceil — ceiling function

1. Definition

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

2. Graph

Ceiling function defined everywhere on 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.

Function codomain is the set of integer numbers.

3. How to use

To calculate ceiling of the number:

ceil(−1.8);

To get ceiling of the complex number:

ceil(−1.8+i*1.2);

To get ceiling of the current result:

ceil(rslt);

To get ceiling of the number z in calculator memory:

ceil(mem[z]);

5. Support

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