## C# Math.Acosh() – Examples

In this tutorial, we will learn about the C# Math.Acosh() method, and learn how to use this method to find the angle whose hyperbolic cosine is the specified number, with the help of examples.

## Acosh(Double)

Math.Acosh(d) returns the angle, in radians, whose hyperbolic cosine is the specified number `d`.

### Syntax

The syntax of Acosh(d) method is

`Math.Acosh(Double d)`

where

Return Value

The method returns Double value.

### Example 1 – Acosh()

In this example, we will give different values ranging from Negative Infinity to Positive Infinity to Acosh() method, and find the corresponding angles, in radians.

C# Program

```using System;

class Example {
static void Main(string[] args) {
Double d, result;

d = Double.NegativeInfinity;
result = Math.Acosh(d);

d = -5;
result = Math.Acosh(d);

d = -1;
result = Math.Acosh(d);

d = 0;
result = Math.Acosh(d);

d = 1;
result = Math.Acosh(d);

d = 5;
result = Math.Acosh(d);

d = Double.PositiveInfinity;
result = Math.Acosh(d);
}
}```

Output

```Acosh(-∞) = NaN radians.