<HEAD> <TITLE> acos - return the arccosine of a float </TITLE> </HEAD> <BODY BACKGROUND=http://www.imaginary.com/~beek/gifs/bg.jpg TEXT=#000000 ALINK=#FFFF00 VLINK=#550000 LINK=#000099> <center> <H1> acos - return the arccosine of a float </H1> </center> <p> <b> float acos( float f ); </b> <p> This efun is available only if PACKAGE_MATH is compiled in to the driver. <p> Returns the arccosine of its argument, `f', measured in radians. <p> See also: <A HREF=asin.html> asin </A>, <A HREF=atan.html> atan </A>, <A HREF=cos.html> cos </A>, <A HREF=sin.html> sin </A>, <A HREF=tan.html> tan </A>