perlfunc
gods
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cos - cosine function
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cos
<FONT SIZE=-1>EXPR</FONT>
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Returns the cosine of
<FONT SIZE=-1>EXPR</FONT> (expressed in radians). If
<FONT SIZE=-1>EXPR</FONT> is omitted, takes cosine of
<CODE>$_</CODE>.
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For the inverse cosine operation, you may use the <CODE>POSIX::acos()</CODE>
function, or use this relation:
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<PRE> sub acos { atan2( sqrt(1 - $_[0] * $_[0]), $_[0] ) }
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