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Manual Reference Pages  - ATAN2 (3)

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atan2, atan2f, atan2l - arc tangent function of two variables

CONTENTS

Synopsis
Description

#include <math.h> 



double atan2(double y, double x); 



float atan2f(float y, float x); 



long double atan2l(long double y, long double x); 

The atan2() function calculates the arc tangent of the two variables x and y. It is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result.

The atan2() function returns the result in radians, which is between -PI and PI (inclusive).

SVID 3, POSIX, BSD 4.3, ISO 9899. The float and long double variants are C99 requirements.

acos(3), asin(3), atan(3), cos(3), sin(3), tan(3)

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