fails:Math#atanh returns Infinity for 1.0
fails:Math#atanh returns -Infinity for -1.0
fails:Math#atanh! returns Infinity for 1.0
fails:Math#atanh! returns -Infinity for -1.0
fails:Math#atanh! raises a TypeError when passed a Complex number
fails:Math.atanh returns Infinity for 1.0
fails:Math.atanh returns -Infinity for -1.0
fails:Math.atanh! returns Infinity for 1.0
fails:Math.atanh! returns -Infinity for -1.0
fails:Math.atanh! raises a TypeError when passed a Complex number
