I revisited that article and ... now I have no idea. Maybe I stumbled into some other trig-related article and came back here. Or maybe this one had some A/B content going on?

The only thing I remember at this point is that I copied and pasted that sentence (I didn't type it.) Even search doesn't find the sentence anywhere but HN.

Search finds that sentence on this blog post https://iquilezles.org/articles/noacos/

Thanks for finding it! Still not sure how I got there while thinking I was at "Even Faster Asin()..."