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,

\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

시도해 보기

// 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

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()`

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® 2026 Language Specification # sec-math.acos