Constant FRAC_1_SQRT_2PI 

pub const FRAC_1_SQRT_2PI: f128 = 0.398942280401432677939946059934381868475858631164934657665926_f128;

🔬This is a nightly-only experimental API. (f128 #116909)

Available on non-crate feature ferrocene_certified only.

1/sqrt(2π)