Inverse sine wave/harmonious distribution

Sine waves are cool for oscillating patterns, but I have a problem: the oscillation flattens smoothly at the extremes (-1, 1) and sharply bypasses centered neutral values (0). I need a distribution equivalent to an inverse sine wave in the material editor, but aside from using asin(x), which is INSANELY expensive, I can’t find it.

The only method that might work is a wrapped texture with a more harmonious distribution, but if there’s a way to compute this mathematically, I’d like to know what it is.