The square root of Ú; equivalently, 1 over the square root of 2, approximately 0.707. SQRT1_2 is static, read-only.
Math
The following function returns 1 over the square root of 2:
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.