Where the ECMA 262 1st Edition did they come from?

Following on from my recent blog post "Where the HTML4.0 did they come from" (October 2005)... I just found two native JavaScript constants that I have hardcoded *at least* 100 times over the years:

Math.SQRT2;
Math.SQRT1_2;

I guess I should be forgiven for not knowing about them yet, they've only been there since 1997.