function acosdf( x ) {
	return addon( x );
}
Computes the arccosine (in degrees) of a single-precision floating-point number.

@private
@param {number} x - input value
@returns {number} arccosine (in degrees)

@example
var v = acosdf( 0.0 );
// returns 90.0

@example
var v = acosdf( 0.5 );
// returns ~60.0

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

var v = acosdf( sqrtf( 2 ) / 2 );
// returns ~45.0

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

var v = acosdf( sqrtf( 3 ) / 2 );
// returns ~30.0

@example
var v = acosdf( NaN );
// returns NaN