===== Arc Sine ======

==== asin( a ) ====

Return the arc sine of a.

=== Description ===

<code>asin( a )</code>

Return the arc sine of a in radians.

=== Parameters ===

| ''a'' | Value [-1 to +1] |

=== Return value ===

arc sine of a

=== Example usage ===

<code>asin( 1 )</code>

Returns 1.57079... (PI/2).