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PHP Math - tan() Function

The PHP Math tan() function returns trigonometric tangent of an angle (angle should be in radians). In special cases it returns the following:

  • If the argument is NAN or an infinity, then the result is NAN.

In the graph below, tan(x) vs x is plotted.

Tan Function




arg Required. Specify the angle in radian.

Return Value

Returns the trigonometric tangent of an angle.


In the example below, tan() function is used to find out the trigonometric tangent of an angle.

echo "tan(pi()/6) = ".tan(pi()/6)."\n";
echo "tan(pi()/4) = ".tan(pi()/4)."\n";
echo "tan(pi()/3) = ".tan(pi()/3)."\n"; 
echo "tan(deg2rad(45)) = ".tan(deg2rad(45))."\n";
echo "tan(M_PI/2) = ".tan(M_PI/2)."\n";
echo "tan(M_PI_4) = ".tan(M_PI_4)."\n"; 
echo "tan(NAN) = ".tan(NAN)."\n";
echo "tan(INF) = ".tan(INF)."\n";

The output of the above code will be:

tan(pi()/6) = 0.57735026918963
tan(pi()/4) = 1
tan(pi()/3) = 1.7320508075689
tan(deg2rad(45)) = 1
tan(M_PI/2) = 1.6331239353195E+16
tan(M_PI_4) = 1
tan(NAN) = NAN
tan(INF) = NAN

❮ PHP Math Functions