NAME

cos — cosine function

SYNOPSIS

#include <math.h>

double
cos(double x);

long double
cosl(long double x);

float
cosf(float x);

DESCRIPTION

The cos() function computes the cosine of x (measured in radians).

SPECIAL VALUES

cos(±0) returns 1.

cos(±infinity) returns a NaN and raises the "invalid" floating-point exception.

VECTOR OPERATIONS

If you need to apply the cos() function to SIMD vectors or arrays, using the following functions provided by the Accelerate.framework may give significantly better performance:

#include <Accelerate/Accelerate.h>

vFloat vcosf(vFloat x);
vFloat vsincosf(vFloat x, vFloat *c);
void vvcosf(float *y, const float *x, const int *n);
void vvcos(double *y, const double *x, const int *n);
void vvsincosf(float *s, float *c, const float *x, const int *n);
void vvsincos(double *s, double *c, const double *x, const int *n);

SEE ALSO

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

STANDARDS

The cos() function conforms to ISO/IEC 9899:2011.