Cosh​(AngouriMath.​Entity)

using System;
using static AngouriMath.MathS.Hyperbolic;

Console.WriteLine(Sinh("x"));
Console.WriteLine(Sinh("x").Differentiate("x").Simplify());
Console.WriteLine(Sinh("x").Differentiate("x").Simplify() == Cosh("x"));
Console.WriteLine("--------------------------");
Console.WriteLine(Cosh("x"));
Console.WriteLine(Cosh("x").Differentiate("x").Simplify());
Console.WriteLine(Cosh("x").Differentiate("x").Simplify() == Sinh("x"));

(e ^ x - e ^ (-x)) / 2
(e ^ x + e ^ (-x)) / 2
True
--------------------------
(e ^ x + e ^ (-x)) / 2
(e ^ x - e ^ (-x)) / 2
True