The Math.SQRT1_2 property represents the square root of 1/2 which is approximately 0.707:

𝙼𝚊𝚝𝚑.𝚂𝚀𝚁𝚃𝟷_𝟸 = 1 2 0.707 \mathtt{\mi{Math.SQRT1_2}} = \sqrt{\frac{1}{2}} \approx 0.707

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Property attributes of Math.SQRT1_2
Writable no
Enumerable no
Configurable no


Math.SQRT1_2 is a constant and a more performant equivalent to Math.sqrt(0.5).

Because SQRT1_2 is a static property of Math, you always use it as Math.SQRT1_2, rather than as a property of a Math object you created (Math is not a constructor).


Using Math.SQRT1_2

The following function returns 1 over the square root of 2:

function getRoot1_2() {
  return Math.SQRT1_2;

getRoot1_2(); // 0.7071067811865476


ECMAScript Language Specification
# sec-math.sqrt1_2

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See also