# Compute the Second Derivative of the Logarithmic value of the gamma Function in R Programming – trigamma() Function

• Last Updated : 12 Jun, 2020

`trigamma()` function in R Language is used to calculate the second derivative of the natural logarithm of the gamma value calculated using the gamma function.
trigamma Function is basically,

`trigamma(x) = d2(ln(factorial(n-1)))/dx2`

Syntax: trigamma(x)

Parameters:
x: Numeric vector

Example 1:

 `# R program to find second derivative ``# of the lgamma value`` ` `# Calling the trigamma() Function``trigamma(``2``)``trigamma(``4``)``trigamma(``5.2``)`

Output:

``` 0.6449341
 0.283823
 0.2119756
```

Example 2:

 `# R program to find second derivative ``# of the lgamma value`` ` `# Creating a vector``x <``-` `c(``2.3``, ``3``, ``1.2``)`` ` `# Calling the trigamma() Function``trigamma(x)`` ` `# Calling trigamma() function``# on negative values``trigamma(``-``2.3``)``trigamma(``-``2``)`

Output:

``` 0.5425375 0.3949341 1.2673772
 14.72591
 Inf
```
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