# Math.Acosh(Double) Method

## Definition

Returns the angle whose hyperbolic cosine is the specified number.

```
public:
static double Acosh(double d);
```

`public static double Acosh (double d);`

`static member Acosh : double -> double`

`Public Shared Function Acosh (d As Double) As Double`

#### Parameters

- d
- Double

A number representing a hyperbolic cosine, where `d`

must be greater than or equal to 1, but less than or equal to PositiveInfinity.

#### Returns

An angle, θ, measured in radians, such that 0 ≤ θ ≤ ∞.

-or-

## Remarks

Multiply the return value by 180/Math.PI to convert from radians to degrees.

This method calls into the underlying C runtime, and the exact result or valid input range may differ between different operating systems or architectures.