---
title: "Roten"
type: "forum-thread"
url: "https://www.webforum.nu/amne/javascript/42637-roten"
topic: "JavaScript"
topic_url: "https://www.webforum.nu/amne/javascript"
author: "Erik Juhlin"
published: "2002-04-28T10:33:52.000Z"
updated: "2002-04-28T13:23:18.000Z"
replies: 4
views: 221
page: 1
pages: 1
language: "sv-SE"
site: "webForum — webforum.nu"
rights: "Upphovsrätten till varje inlägg tillhör dess författare."
attribution: "Citera som: webForum, https://www.webforum.nu/amne/javascript/42637-roten"
---

# Roten

## #1 — Erik Juhlin, 2002-04-28T10:33Z

Hur tar man roten av något med javascript?

Permalänk: https://www.webforum.nu/p/42637

## #2 — hypatia, 2002-04-28T11:27Z

Math.sqrt(x)

Permalänk: https://www.webforum.nu/p/662049

## #3 — Erik Juhlin, 2002-04-28T12:44Z

Ah! Tack hypatia! :)

Permalänk: https://www.webforum.nu/p/662092

## #4 — Erik Juhlin, 2002-04-28T12:52Z

Hur kollar man om det returnerar "NaN"?
När jag skriver alert(Math.sqrt(-1) == "NaN"); så blir det false... :(

Permalänk: https://www.webforum.nu/p/662095

## #5 — Jojoxx, 2002-04-28T13:23Z

```
alert(isNaN(Math.sqrt(-1)))
```

Permalänk: https://www.webforum.nu/p/662103

---

Tråden på webben: https://www.webforum.nu/amne/javascript/42637-roten