The **acosh()** function in R is **“used to calculate the inverse hyperbolic cosine of a value“**. The hyperbolic arccosine is the inverse of the hyperbolic cosine function, which means that acosh(x) = cosh-1(x).

**Syntax**

`acosh(x)`

**Parameters**

**x:** It is a numeric value, array, or vector.

**Example 1**

To calculate the hyperbolic arccosine in R, you can use the **acosh()** function. The inverse hyperbolic cosine function is defined by **x == cosh(y)**.

`acosh(1)`

**Output**

`[1] 0`

If you pass the 0 to the atanh() function, it will return 0.

`acosh(0)`

**Output**

`[1] 0`

**Example 2**

Define and pass a complex value to the acosh() function.

```
dt <- 8 + 9i
acosh(dt)
```

**Output**

`[1] 3.181721+0.845865i`

**Example 3**

We can use the seq() function to create a series of values and pass that to the plot() function, creating a line chart.

```
dt <- seq(-1, 1, by = 0.01)
plot(dt, acosh(dt), type = "l", col = "red")
```

**Output**

```
Warning message:
In acosh(dt) : NaNs produced
```

The function returns the NaN value, so it can’t draw a graph based on that value.

**Example 4**

To create a Vector in R, use the c() function. Then pass that vector to the acosh() function.

```
rv <- c(-1, 0.5, 0, 0.5, 1)
acosh(rv)
```

**Output**

```
[1] NaN NaN NaN NaN 0
Warning message:
In acosh(rv) : NaNs produced
```

**Example 5**

The pi is an inbuilt constant in R programming, and its value is 3.141593.

Let’s find the pi constant’s acosh() value.

`acosh(pi)`

**Output**

`[1] 1.811526`

Let’s see another example of pi.

`acosh(pi / 4)`

**Output**

```
[1] NaN
Warning message:
In acosh(pi/4) : NaNs produced
```

That is it for acosh() function in R.

Krunal Lathiya is a Software Engineer with over eight years of experience. He has developed a strong foundation in computer science principles and a passion for problem-solving. In addition, Krunal has excellent knowledge of Data Science and Machine Learning, and he is an expert in R Language.