tan() — Calculate Tangent

Format

#include <math.h>
double tan(double x);

Language Level: ANSI

Threadsafe: Yes.

Description

The tan() function calculates the tangent of x, where x is expressed in radians. If x is too large, a partial loss of significance in the result can occur and sets errno to ERANGE. The value of errno may also be set to EDOM.

Return Value

The tan() function returns the value of the tangent of x.

Example that uses tan()

This example computes x as the tangent of π/4.

#include <math.h>
#include <stdio.h>
 
int main(void)
{
   double pi, x;
 
   pi = 3.1415926;
   x = tan(pi/4.0);
 
   printf("tan( %lf ) is %lf\n", pi/4, x);
}
 
/******************  Output should be similar to:  ****************
 
tan( 0.785398 ) is 1.000000
*/

Related Information

• acos() — Calculate Arccosine
• asin() — Calculate Arcsine
• atan() – atan2() — Calculate Arctangent
• cos() — Calculate Cosine
• cosh() — Calculate Hyperbolic Cosine
• sin() — Calculate Sine
• sinh() — Calculate Hyperbolic Sine
• tanh() — Calculate Hyperbolic Tangent
• <math.h>