# e (2.718...) function

To use this function, choose Calc > Calculator.

Inserts the constant e, rounded to six decimal places (2.718281).

e is the base of the natural logarithm function. The constant e is an irrational number, and is defined by the infinite sum 1/0! + 1/1! + 1/2! + 1/3! + 1/4! + 1/5!...

## Syntax

E()

You can also use the predefined constant K999.

## Example

Column Calculator expression Result
C1 contains 15 C1*E() 40.77422742688567

## Uses

Also called Euler's number or Napier's constant, e can be used to calculate exponential growth and decay, and probability values. In statistics, e is often used in formulas to model various data distributions, including the normal bell-shaped curve. It is also used to calculate probabilities for response variables in logistic regression.

The constant e also has useful applications in engineering, such as electrical transportation (to calculate length, weight, and stress of cables and conducting wires), superstructure (to compute elastic curves and deflection of suspension bridges), and aerospace (to determine ideal surface coatings for aircraft).