Math.acos()

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.acos() 함수는 주어진 수의 아크코사인 값을 숫자(라디안)로 반환합니다. 즉,

x [ - 1 ; 1 ] , Math.acos ( x ) = arccos ( x ) = the unique y [ 0 ; π ] such that cos ( y ) = x \forall x \in [{-1};1],;\mathtt{\operatorname{Math.acos}(x)} = \arccos(x) = \text{ the unique } ; y \in [0; \pi] , \text{such that} ; \cos(y) = x

시도해보기

// Calculates angle of a right-angle triangle in radians
function calcAngle(adjacent, hypotenuse) {
  return Math.acos(adjacent / hypotenuse);
}

console.log(calcAngle(8, 10));
// Expected output: 0.6435011087932843

console.log(calcAngle(5, 3));
// Expected output: NaN

구문

js
Math.acos(x);

매개변수

x

각도를 나타내는 라디안.

반환 값

-1과 1 사이의 값이 주어진 경우, 그 값의 아크코사인. 아닐 경우 NaN

설명

The Math.acos() method returns a numeric value between 0 and π radians for x between -1 and 1. If the value of x is outside this range, it returns NaN.

Because acos() is a static method of Math, you always use it as Math.acos(), rather than as a method of a Math object you created (Math is not a constructor).

예제

Using Math.acos()

js
Math.acos(-2); // NaN
Math.acos(-1); // 3.141592653589793
Math.acos(0); // 1.5707963267948966
Math.acos(0.5); // 1.0471975511965979
Math.acos(1); // 0
Math.acos(2); // NaN

For values less than -1 or greater than 1, Math.acos() returns NaN.

명세

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

브라우저 호환성

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
acos

Legend

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

Full support
Full support

See also