tan(), tanf(), tanl()

Calculate the tangent of an angle

Synopsis:

#include <math.h>

double tan( double x );

float tanf( float x );

long double tanl( long double x );

Arguments:

x
The angle, in radians, for which you want to compute the tangent.

Library:

libm

Use the -l m option to qcc to link against this library.

Description:

These functions compute the tangent (specified in radians) of x. A large magnitude argument may yield a result with little or no significance.

Returns:

The tangent value. If x is NAN or infinity, NAN is returned. For a correct value that would cause an underflow, these functions return 0.0.

If an error occurs, these functions return 0, but this is also a valid mathematical result. If you want to check for errors, set errno to 0, call the function, and then check errno again. These functions don't change errno if no errors occurred.

Examples:

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

int main( void )
  {
    printf( "%f\n", tan(.5) );

    return EXIT_SUCCESS;
  }

produces the output:

0.546302

Classification:

ANSI, POSIX 1003.1

Safety:  
Cancellation point No
Interrupt handler No
Signal handler No
Thread Yes

Last modified: 2013-12-23

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