erf(−x)
Odd function: −erf(x)
Key properties: erf(0) = 0 · erf(∞) = 1 · erf is odd: erf(−x) = −erf(x) · erf(x) + erfc(x) = 1
Statistics link: Φ(x) = ½[1 + erf(x/√2)] where Φ is the standard normal CDF
Relation at x=1: erf(1) ≈ 0.8427 (about 84.27% probability within 1σ for normal distribution)