Calculate the tangent (tan) or hyperbolic tangent (tanh).
doubletan(doublex**);**
doubletanh(doublex**);**
| Routine | Required Header | Compatibility |
| tan | <math.h> | ANSI, Win 95, Win NT |
| tanh | <math.h> | ANSI, Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
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, in which case the function generates a _TLOSS error and returns an indefinite (same as a quiet NaN). You can modify error handling with _matherr.
tanh returns the hyperbolic tangent of x. There is no error return.
Parameter
x
Angle in radians
Example
/* TAN.C: This program displays the tangent of pi / 4
* and the hyperbolic tangent of the result.
*/
#include <math.h>
#include <stdio.h>
void 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 );
}
Output
tan( 0.785398 ) = 1.000000
tanh( 1.000000 ) = 0.761594