###Function###
ACos

###Description###
Calculates the arcCosine of a number.

###Syntax###
ACos ( expression )


###Parameters###
@@ParamTable@@
expression
	Any value between -1 and 1 inclusive.
@@End@@

###ReturnValue###
Returns the trigonometric arccosine of the number.  Result is in radians.


###Remarks###
<a href="ACos.htm">ACos</a>(x) is mathematically defined only for -1 <u>&lt;</u> x <u>&lt;</u> 1, so <a href="ACos.htm">ACos()</a> tends to return -1.#IND for other values of x.


###Related###
ASin, ATan, Cos, Sin, Tan


###Example###
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