tan, tanf, tanh, tanhf

Calculate the tangent (tan or tanf) or hyperbolic tangent (tanh or tanhf).

double tan(
   double x 
float tan(
   float x 
);  // C++ only
long double tan(
   long double x
);  // C++ only
float tanf(
   float x 
double tanh(
   double x 
float tanh(
   float x 
);  // C++ only
long double tanh(
   long double x
);  // C++ only
float tanhf(
   float x 


  • x
    Angle in radians.

Return Value

tan returns the tangent of x. If x is greater than or equal to 263, or less than or equal to –263, a loss of significance in the result occurs.


SEH Exception

Matherr Exception




± ∞ (tan, tanf)



tanh returns the hyperbolic tangent of x. There is no error return.


C++ allows overloading, so users can call overloads of tan and tanh that take float or long double types. In a C program, the tan and tanh functions always take and return double.



Required header

tan, tanf, tanh, tanhf


For additional compatibility information, see Compatibility in the Introduction.


// crt_tan.c
// This program displays the tangent of pi / 4
// and the hyperbolic tangent of the result.

#include <math.h>
#include <stdio.h>

int main( void )
   double pi = 3.1415926535;
   double x, y;

   x = tan( pi / 4 );
   y = tanh( x );
   printf( "tan( %f ) = %f\n", pi/4, x );
   printf( "tanh( %f ) = %f\n", x, y );
tan( 0.785398 ) = 1.000000
tanh( 1.000000 ) = 0.761594

.NET Framework Equivalent

See Also


Floating-Point Support

Long Double

acos, acosf

asin, asinf

atan, atanf, atan2, atan2f

cos, cosf, cosh, coshf

sin, sinf, sinh, sinhf