Arccoversine

Compute the inverse coversed sine.

The inverse coversed sine is defined as

$$\mathop{\mathrm{acoversin}}(\theta) = \arcsin(1-\theta)$$

Usage

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

acoversin( x )

Computes the inverse coversed sine.

var v = acoversin( 0.0 );
// returns ~1.5708

v = acoversin( 3.141592653589793/2.0 );
// returns ~-0.6075

v = acoversin( 3.141592653589793/6.0 );
// returns ~0.4966

If x < 0, x > 2, or x is NaN, the function returns NaN.

var v = acoversin( -1.0 );
// returns NaN

v = acoversin( 3.14 );
// returns NaN

v = acoversin( NaN );
// returns NaN

Examples

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

var x = uniform( 100, 0.0, 2.0, {
    'dtype': 'float64'
});

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

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C APIs

Usage

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

stdlib_base_acoversin( x )

Computes the inverse coversed sine of a double-precision floating-point number (in radians).

double out = stdlib_base_acoversin( 3.141592653589793/2.0 );
// returns ~-0.6075

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_acoversin( const double x );

Examples

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

int main( void ) {
    const double x[] = { -5.0, -3.89, -2.78, -1.67, -0.56, 0.56, 1.67, 2.78, 3.89, 5.0 };

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

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See Also

• @stdlib/math/base/special/acovercos: compute the inverse coversed cosine.
• @stdlib/math/base/special/aversin: compute the inverse versed sine.
• @stdlib/math/base/special/coversin: compute the coversed sine.
• @stdlib/math/base/special/versin: compute the versed sine.