Museum

Home

Lab Overview

Retrotechnology Articles

⇒ Online Manual

Media Vault

Software Library

Restoration Projects

Artifacts Sought

SIN(3M)

NAME

sin, cos, tan, asin, acos, atan, atan2 − trigonometric functions

USAGE

#include <math.h>
 
double sin(x) double x;
 
double cos(x) double x;
 
double tan(x) double x;
 
double asin(x) double x;
 
double acos(x) double x;
 
double atan(x) double x;
 
double atan2(x, y) double x, y;

DESCRIPTION

Sin, cos, and tan return trigonometric functions of radian arguments.  The magnitude of the argument should be checked by the caller to make sure the result is meaningful. 

Asin returns the arcsine in the range −π/2 to π/2. 

Acos returns the arccosine in the range zero to π. 

Atan returns the arctangent of x in the range −π/2 to π/2. 

Atan2 returns the arctangent of x/y in the range −π to π. 

NOTES

The value of tan for arguments greater than about 231 is meaningless. 

DIAGNOSTICS

Arguments of magnitude greater than one cause asin and acos to return value zero; errno is set to EDOM.  The value of tan at its singular points is HUGE, and errno is set to ERANGE. 

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026