9.31.7 Math Builtins
The following built-in functions may be used to generate a
floating-point value.  All return a floating-point value except
$cvi, $int, and $sgn, which return an integer
value.
     
$acos(expr)- Returns the floating point arccosine of expr.
     
 $asin(expr)- Returns the floating point arcsine of expr.
     
 $atan(expr)- Returns the floating point arctangent of expr.
     
 $atan2(expr1,expr2)- Returns the floating point arctangent of expr1 / expr2.
     
 $ceil(expr)- Returns the smallest integer not less than expr as floating point.
     
 $cosh(expr)- Returns the floating point hyperbolic cosine of expr.
     
 $cos(expr)- Returns the floating point cosine of expr.
     
 $cvf(expr)- Returns the integer value expr converted to floating-point.
     
 $cvi(expr)- Returns the floating point value expr converted to integer.
     
 $exp(expr)- Returns the floating point value e ^ expr.
     
 $fabs(expr)- Returns the floating point absolute value of expr.
     
 $floor(expr)- Returns the largest integer that is not greater than expr as
floating point.
     
 $fmod(expr1,expr2)- Returns the floating point remainder of expr1 / expr2.
     
 $int(expr)- Returns 1 if expr evaluates to an integer, zero otherwise.
     
 $ldexp(expr1,expr2)- Returns the floating point value expr1 * 2 ^ expr2.
     
 $log10(expr)- Returns the base 10 logarithm of expr.
     
 $log(expr)- Returns the natural logarithm of expr.
     
 $max(expr1,expr2)- Returns the floating point maximum of expr1 and expr2.
     
 $min(expr1,expr2)- Returns the floating point minimum of expr1 and expr2.
     
 $pow(expr1,expr2)- Returns the floating point value expr1 ^ expr2.
     
 $round(expr)- Returns the nearest integer to expr as a floating point number.
     
 $sgn(expr)- Returns -1, 0, or 1 based on the sign of expr.
     
 $sin(expr)- Returns the floating point sine of expr.
     
 $sinh(expr)- Returns the floating point hyperbolic sine of expr.
     
 $sqrt(expr)- Returns the floating point square root of expr.
     
 $tan(expr)- Returns the floating point tangent of expr.
     
 $tanh(expr)- Returns the floating point hyperbolic tangent of expr.
     
 $trunc(expr)- Returns the integer value of expr truncated towards zero as
floating point.