.\"return the arccosine of a float .DT acos $MUDNAME$ driver help acos .SH Name .SI 5 acos() - return the arccosine of a float .EI .SH Synopsis .SI 5 float acos( float f ); .EI .SH Description .SP 5 5 Returns the arccosine of its argument, `f', measured in radians. .EP .SH See also .SI 5 asin(), atan(), cos(), sin(), tan() .EI