/** Function calls

    sqrt(25)  // square root of 25. Its value is 5.0.
    abs(Ð7)   // absolute value of Ð7. Its value is 7.
    cos(0)    // cosine of angle 0. It value is 1.0
    min(5, 7) // minimum of 5 and 7. Its value is 5.

Form: <function-name> ( <arguments> )
       
    <arguments>: list of expressions separated by ','
    
 Don't use "actual parameter". Use "argument"
        
    1  +  min(5, 7) * 2     // value is 11
        
 Functions defined in class Math 
 
 Math.sqrt(double)    // Yields a double.
    Math.sqrt(25.0) // The square root of 25.0. Its value is 5.0.
    Math.sqrt(5.0) // The square root of 5.0. Its value is 2.23606797749979.
    Math.sqrt(25)  // The square root of 25.0. Its value is 5.0.
    Math.sqrt(5)  // The square root of 5.0. Its value is 2.23606797749979.

 Math.abs(int)        // Yields an int.
    Math.abs(5)  // The absolute value of 5. Its value is 5.
    Math.abs(-5)  // The absolute value of -5. Its value is 5.

 Math.abs(double)        // Yields a double.
    Math.abs(5.0)  // The absolute value of 5.0. Its value is 5.0.
    Math.abs(-5.0) // The absolute value of -5.0. Its value is 5.0.

 Math.min(int, int)      // Yields an int.
    Math.min(5, 7) // minimum of 5 and 7. Its value is 5.
    Math.min(5, -7) // minimum of 5 and -7. Its value is -7.
    
Math.min(double, double)// Yields a double.
    Math.min(5.0, 7.0) // minimum of 5.0 and 7.0. Its value is 5.0.
    Math.min(5.0, -7) // minimum of 5.0 and -7. Its value is -7.0.
    
Three useful functions are
   Math.round(double), Math.floor(double), Math.ceil(double).

        
   Math.round(double)     round to nearest integer
   Math.floor(double)     floor
   Math.ceil(double)      ceiling
 
 ___________ ceiling 6
 
     5.8
   
     5.5
 
     5.3
     
 ___________ floor 5
 
 List of Math. functions in in a table on page 24 of Gries/Gries
 
 
 
*/