Compute the hyperbolic arccosine of a number.
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> Compute the [hyperbolic arccosine][inverse-hyperbolic] of a number.
``bash`
npm install @stdlib/math-base-special-fast-acosh
`javascript`
var acosh = require( '@stdlib/math-base-special-fast-acosh' );
#### acosh( x )
Computes the [hyperbolic arccosine][inverse-hyperbolic] of a number (in radians).
`javascript
var v = acosh( 1.0 );
// returns 0.0
v = acosh( 2.0 );
// returns ~1.317
v = acosh( 0.5 );
// returns NaN
`
The domain of x is restricted to [1,+infinity). If x < 1, the function will return NaN.
`javascript`
var v = acosh( 0.0 );
// returns NaN
- For large x, the function will overflow.
`javascript`
var v = acosh( 1.0e308 );
// returns Infinity
// (expected 709.889355822726)
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var acosh = require( '@stdlib/math-base-special-fast-acosh' );
var opts = {
'dtype': 'float64'
};
var x = uniform( 103, 1.0, 5.0, opts );
logEachMap( 'acosh(%0.4f) = %0.4f', x, acosh );
`
*
`c`
#include "stdlib/math/base/special/fast/acosh.h"
#### stdlib_base_fast_acosh( x )
Computes the [hyperbolic arccosine][inverse-hyperbolic] of a double-precision floating-point number.
`c
double out = stdlib_base_fast_acosh( 1.0 );
// returns 0.0
out = stdlib_base_fast_acosh( 2.0 );
// returns ~1.317
`
The function accepts the following arguments:
- x: [in] double input value.
`c`
double stdlib_base_fast_acosh( const double x );
`c
#include "stdlib/math/base/special/fast/acosh.h"
#include
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_fast_acosh( x[ i ] );
printf( "acosh(%lf) = %lf\n", x[ i ], v );
}
}
`
*
- [@stdlib/math-base/special/acosh][@stdlib/math/base/special/acosh]: compute the hyperbolic arccosine of a double-precision floating-point number.
*
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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---
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[inverse-hyperbolic]: https://en.wikipedia.org/wiki/Inverse_hyperbolic_function
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