Math.acosh()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Math.acosh() 靜態方法回傳數字的反雙曲餘弦值。也就是說,

x1,𝙼𝚊𝚝𝚑.𝚊𝚌𝚘𝚜𝚑(𝚡)=arcosh(x)=the unique y0 such that cosh(y)=x=ln(x+x21)\begin{aligned}\forall x \geq 1,\;\mathtt{\operatorname{Math.acosh}(x)} &= \operatorname{arcosh}(x) = \text{the unique } y \geq 0 \text{ such that } \cosh(y) = x\\&= \ln\left(x + \sqrt{x^2 - 1}\right)\end{aligned}

嘗試一下

console.log(Math.acosh(0.999999999999));
// Expected output: NaN

console.log(Math.acosh(1));
// Expected output: 0

console.log(Math.acosh(2));
// Expected output: 1.3169578969248166

console.log(Math.acosh(2.5));
// Expected output: 1.566799236972411

語法

js
Math.acosh(x)

參數

x

一個大於或等於 1 的數字。

回傳值

x 的反雙曲餘弦值。如果 x 小於 1,則回傳 NaN

描述

由於 acosh()Math 的靜態方法,你必須使用 Math.acosh() 來呼叫它,而非呼叫你建立的 Math 物件的方法(Math 並非建構子)。

範例

使用 Math.acosh()

js
Math.acosh(0); // NaN
Math.acosh(1); // 0
Math.acosh(2); // 1.3169578969248166
Math.acosh(Infinity); // Infinity

規範

Specification
ECMAScript® 2025 Language Specification
# sec-math.acosh

瀏覽器相容性

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
acosh

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

參見