# How to Use the acosh() Function in R

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

`` 0``

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

``acosh(0)``

Output

`` 0``

### Example 2

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

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

Output

`` 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

`````` 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

`` 1.811526``

Let’s see another example of pi.

``acosh(pi / 4)``

Output

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

That is it for acosh() function in R.