TAN():

TAN(X);

<?Php
echo TAN(PI()); // Output is  0 
echo "<br>";
echo TAN(PI()/2); // Output  is infinity 
echo "<br>";
echo ROUND(TAN(PI()/3),2); // Output is 1.73
echo "<br>";
echo TAN(PI()/4); // Output is 1 
?>

deg2rad() with TAN()

<?Php
echo TAN(deg2rad(0)); // Output  is 0
echo "<br>";
echo TAN(deg2rad(90)); // Output is 1.6331239353195E+16  // same as infinity 
echo "<br>";
echo TAN(deg2rad(180)); // Output  is -1.2246467991474E-16//  same as 0
?>

Example: Handling Tan of 90 Degrees

$angle = 90;
echo tan(deg2rad($angle));  // Output: Large value (Infinity)

Example: Calculating Slope of a Triangle

$angle = 45;
$adjacent = 10;
$opposite = $adjacent * tan(deg2rad($angle));  // Output: 10 (Height of the triangle)
echo $opposite;

Example: Calculating Tan for Small Angles

$angle = 30;
echo tan(deg2rad($angle));  // Output: 0.57735026918963

Example: Tan of Negative Angles

$angle = -45;
echo tan(deg2rad($angle));  // Output: -1

Example: Using Tan to Find Height from Distance and Angle

$angle = 30;  // Angle of elevation
$distance = 100;  // Distance from object
$height = $distance * tan(deg2rad($angle));  // Calculate height
echo $height;  // Output: 57.735026918963

Plotting of SIN & SIN curves by using PHP GD function with deg2rad()