public static double acosh(double a) {return Math.log(Math.sqrt(a * a - 1.0d) + a);}

public static double acosh ( double a ) { return Math . log ( Math . sqrt ( a * a - 1.0d ) + a ) ; }
public static double Acosh(double a){return Math.Log(Math.Sqrt(a * a - 1.0d) + a);}
