# Mathematics - Exponential (Euler's number)

$e \approx 2:71828$ is the scientific constant, the exponential. Euler's number

The number e is an important mathematical constant that is the base of the natural logarithm.

The number e can be defined to be:

• the unique real number a such that

$$ln(a) = 1$$

• the limit of the below hyperbola as n approaches infinity,

$$(1 + \frac{1}{n})^n$$

## Property

e to anything is positive.

### Inverse

ln is the inverse function.

$$ln(e(x))=x$$

Whenever you see exponentials the first thing you want to do is take the logs.