Compute the cosine of an angle measured in degrees.
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> Computes the [cosine][trigonometric-functions] of an angle measured in degrees.
``bash`
npm install @stdlib/math-base-special-cosd
`javascript`
var cosd = require( '@stdlib/math-base-special-cosd' );
#### cosd( x )
Computes the [cosine][trigonometric-functions] of x (in degrees).
`javascript
var v = cosd( 0.0 );
// returns 1.0
v = cosd( 60.0 );
// returns ~0.5
v = cosd( 90.0 );
// returns 0.0
v = cosd( NaN );
// returns NaN
`
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var cosd = require( '@stdlib/math-base-special-cosd' );
var opts = {
'dtype': 'float64'
};
var x = uniform( 100, -180, 180, opts );
logEachMap( 'cosd(%0.4f) = %0.4f', x, cosd );
`
*
`c`
#include "stdlib/math/base/special/cosd.h"
#### stdlib_base_cosd( x )
Computes the [cosine][trigonometric-functions] of x (in degrees).
`c
double out = stdlib_base_cosd( 0.0 );
// returns 1.0
out = stdlib_base_cosd( 60.0 );
// returns ~0.5
`
The function accepts the following arguments:
- x: [in] double input value.
`c`
double stdlib_base_cosd( const double x );
`c
#include "stdlib/math/base/special/cosd.h"
#include
int main( void ) {
const double x[] = { 0.0, 30.0, 45.0, 60.0, 90.0 };
double y;
int i;
for ( i = 0; i < 5; i++ ) {
y = stdlib_base_cosd( x[ i ] );
printf( "cosd(%lf) = %lf\n", x[ i ], y );
}
}
`
*
- [@stdlib/math-base/special/tand][@stdlib/math/base/special/tand]: compute the tangent of an angle measured in degrees.
*
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/math-base-special-cosd/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-cosd/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-cosd/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-cosd/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-cosd/tree/esm
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[trigonometric-functions]: https://en.wikipedia.org/wiki/Trigonometric_functions
[@stdlib/math/base/special/tand]: https://www.npmjs.com/package/@stdlib/math-base-special-tand