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atan(3)

Canonical URL: /atan.3/

ATAN(3) Library Functions Manual ATAN(3)

atan, atanf, atanlarc tangent functions of one variable

/* -lm */
#include <math.h>

double
atan(double x);

float
atanf(float x);

long double
atanl(long double x);

The () function computes the principal value of the arc tangent of x in the range [-pi/2, +pi/2]. The () function is a single precision version of atan(). The () function is an extended precision version of atan().

acos(3), asin(3), atan2(3), cos(3), cosh(3), sin(3), sinh(3), tan(3), tanh(3)

OpenBSD 7.9 June 7, 2025 ATAN(3)

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