The **`tanh()` function** in Perl returns a number's hyperbolic tangent in radians. 

The following illustration shows the mathematical representation of the `tanh()` function.

# 
## Syntax
```perl
tanh(num)
```
## Parameter
This function requires a number that represents an angle in radians as a parameter.

To convert degrees to radians, use the following function in Perl.
```perl
deg2rad(angleInDegrees)
```

## Return value
`tanh()` returns the hyperbolic tangent of a  number (in radians) that is sent as a parameter.

* If the value of `num` is  #key# NaN :not a number #key#, then the returned value is `NaN`.
* If the value of `num` is positive infinity, then the returned value is `1`.
* If the value of `num` is negative infinity, then the returned value is `-1`.

## Code


#this header for deg2rad() function
use Math::Trig;

#Positive number in radians
$a = tanh(2.3);
print "tanh(2.3): $a \n";

#negative number in radians
$b = tanh(-2.3);
print "tanh(-2.3): $b \n";

#converting the degrees angle into radians and then applying tanh()
#degrees = 45
$rad = deg2rad(45);
$c = tanh($rad);
print "tanh($rad): $c \n";

#Inf values
$d = tanh(Inf);
print "tanh(Inf): $d \n";

$e = tanh(-Inf);
print "tanh(-Inf): $e \n";

#NaN value
$f = tanh(NaN);
print "tanh(NaN): $f \n";

What is tanh() in Perl?

The tanh() function in Perl returns a number’s hyperbolic tangent in radians.