ReferenceExpressionsTrigonometryArc SineReturn the arc sine of a.asin( a )# Return the arc sine of a. Description# asin( a ) Return the arc sine of a in radians. Parameters# a Value [-1 to +1] Return value# arc sine of a Example usage# asin( 1 ) Returns 1.57079… (PI/2). Last updated Sep 2, 2019PreviousArc CosineNextArc Tangent