README.md

acosd

Compute the arccosine in degrees of a double-precision floating-point number.

Usage

var acosd = require( '@stdlib/math/base/special/acosd' );

acosd( x )

Computes the arccosine (in degrees) of a double-precision floating-point number.

var sqrt = require( '@stdlib/math/base/special/sqrt' );
var v = acosd( 0.0 );
// returns 90.0

v = acosd( 0.5 );
// returns ~60.0

v = acosd( sqrt( 2 ) / 2 );
// returns ~45.0

v = acosd( sqrt( 3 ) / 2 );
// returns ~30.0

v = acosd( NaN );
// returns NaN

The domain of x is restricted to [-1,1]. If |x| > 1, the function returns NaN.

var v = acosd( -3.14 );
// returns NaN

Examples

var uniform = require( '@stdlib/random/array/uniform' );
var logEachMap = require( '@stdlib/console/log-each-map' );
var acosd = require( '@stdlib/math/base/special/acosd' );

var x = uniform( 100, -1.0, 1.0, {
    'dtype': 'float64'
});

logEachMap( 'acosd(%0.4f) = %0.4f', x, acosd );

---

C APIs

Usage

#include "stdlib/math/base/special/acosd.h"

stdlib_base_acosd( x )

Computes the arccosine (in degrees) of a double-precision floating-point number.

double out = stdlib_base_acosd( 0.0 );
// returns 90.0

out = stdlib_base_acosd( 0.5 );
// returns ~60.0

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_acosd( const double x );

Examples

#include "stdlib/math/base/special/acosd.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { 1.0, 1.45, 1.89, 2.33, 2.78, 3.22, 3.66, 4.11, 4.55, 5.0 };

    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_acosd( x[ i ] );
        printf( "acosd(%lf) = %lf\n", x[ i ], v );
    }
}

---

See Also

• @stdlib/math/base/special/acos: compute the arccosine of a double-precision floating-point number.
• @stdlib/math/base/special/acosh: compute the hyperbolic arccosine of a double-precision floating-point number.
• @stdlib/math/base/special/asind: compute the arcsine (in degrees) of a double-precision floating-point number.
• @stdlib/math/base/special/atand: compute the arctangent(in degrees) of a double-precision floating-point number.