 ArcCos(x: real): real;</h4><br>
	Arccos returns the inverse cosine of its argument x. The argument x should lie between -1 and 1 (borders included).<br><ul></ul></td></tr>
<tr><td class='tname fname'>Tan</td><td class='tdesc'><h4>function Tan(x: Real): Real;</h4><br>
	Tan returns the tangent of x. The argument x must be in radians.<br><ul></ul></td></tr>
<tr><td class='tname fname'>Ceil</td><td class='tdesc'><h4>function Ceil(a: real): smallint;</h4><br>
	Ceil returns the lowest integer number greater than