perl function cos

The cos function in Perl is used to return the cosine of a given angle in radians. Here's an example of how to use cos:

use Math::Trig;

# Calculate the cosine of 45 degrees
my $angle = 45;
my $radians = deg2rad($angle);
my $cosine = cos($radians);

print "The cosine of $angle degrees is $cosine\n";

In this example, the Math::Trig module is used to convert the angle from degrees to radians using the deg2rad function. The angle is then passed to the cos function, which calculates the cosine of the angle in radians. The result is stored in the $cosine variable and printed to the console.

It's important to note that the cos function expects its argument to be in radians, not degrees. Therefore, it's necessary to convert the angle from degrees to radians using a function like deg2rad before passing it to cos.