# C++ Math acosh()

The function computes the arc hyperbolic cosine of an angle given in radian.

Where, an arc hyperbolic cosine is the inverse operation of hyperbolic cosine.

cosh-1x = acosh(x);

## Syntax

Suppose an angle is 'x':

## Parameter

x: The value whose arc hyperbolic cosine is to be computed.

## Return value

It returns the arc hyperbolic cosine of x.

## Example 1

Let's see the simple example when the value of degree is integer type.

Output:

```Value of degree is : 30
cosh(x) : 1.14009
acosh(x) : -nan
```

In this example, acosh() function computes the arc hyperbolic cosine of x and returns the value -nan.

## Example 2

Let's see the simple example when the value of degree is float type.

Output:

```Value of degree is : 15.7
cosh(x) : 1.03443
acosh(x) : -nan
```

In this example, acosh() computes the arc hyperbolic cosine of x and returns the value -nan.

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