> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/r/real_constants_and_functions.md).

# Real constants and functions

```ruby
Num.e     # e
Num.pi    # pi
x.sqrt    # square root
x.log     # natural logarithm
x.log10   # base 10 logarithm
x.exp     # e raised to the power of x
x.abs     # absolute value
x.floor   # floor
x.ceil    # ceiling
x**y      # exponentiation
```