Infinity Symbol
The infinity symbol is a mathematical symbol that represents an infinitely large number.
The infinity symbol is written with the Lemniscate symbol:
∞
It represents an infinitely positive big number.
When we want to write an infinitely negative number we should write:
-∞
When we want to write an infinitely small number we should write:
1/∞
Is infinity a real number?
Infinity is not a number. It does not represent a specific number, but an infinitely large quantity.
Infinity rules & properties
Name | Key type |
---|---|
Positive infinity | ∞ |
Negative infinity | -∞ |
Infinity difference | ∞ - ∞ is undefined |
Zero product | 0 · ∞ is undefined |
Infinity quotient | ∞ / ∞ is undefined |
Real number sum | x + ∞ = ∞, for x∈ℝ |
Positive number product | x · ∞ = ∞, for x>0 |
How to type infinity symbol on keyboard
Platform | Key type | Description |
---|---|---|
PC windows | Alt+236 | Hold the ALT key and type 236 on the num-lock keypad. |
Macintosh | Option+5 | Hold the Option key and press 5 |
Microsoft word | Insert > Symbol > ∞ | Menu selection: Insert > Symbol > ∞ |
Alt+236 | Hold the ALT key and type 236 on the num-lock keypad. | |
Microsoft excel | Insert > Symbol > ∞ | Menu selection: Insert > Symbol > ∞ |
Alt+236 | Hold the ALT key and type 236 on the num-lock keypad. | |
Web page | Ctrl+C, Ctrl+V | Copy ∞ from here and paste it in your web page. |
Ctrl+C, Ctrl+V | Copy ∞ from here and paste it in your Facebook page. | |
HTML | ∞ or ∞ | |
ASCII code | 236 | |
Unicode | U+221E | |
LaTeX | \infty | |
MATLAB | \infty | Example: title('Graph to \infty') |
Infinity in set theory
Aleph-null () is the infinite number of elements (cardinality) of the natural numbers set ().
Aleph-one () is the infinite number of elements (cardinality) of the countable ordinal numbers set (ω_{1}).