# Built-in constants

Calculabo contains various **built-in constants** that are common in mathematics.

## List of constants

The following five mathematical constants are included as built-in variables in Calculabo:

**pi**$\pi $,**Euler’s number**or**Napier’s constant**$e$,**Euler-Mascheroni constant**or**Euler’s constant**$\gamma $,- the
**golden ratio**$\varphi \u2254\frac{1+\sqrt{5}}{2}$, and - the
**imaginary unit**$i\u2254\sqrt{-1}$.

These constants are also visible in the *Memory* pane in the Calculabo interface.

### Example

$$\pi $$

$$3.14159265358979$$

$$e$$

$$2.71828182845905$$

$$\gamma $$

$$0.577215664901533$$

$$\varphi $$

$$1.61803398874989$$

$$i$$

$$i$$

### Example

$${e}^{\pi \cdot i}+1$$

$$0$$

$$\varphi -\frac{1}{\varphi}$$

$$1$$