The ACOS function returns a numeric value in radians that approximates the arccosine of argument-1. The type of this function
                  is numeric. 
                   
               
            
 
            
            
               General Format
 
               	  
               	 
 
               
              
            
            
               Arguments
 
               	  
                
                  	 
                  - Argument-1 must be class numeric. 
                     	 
                  
  
                  	 
                  - The value of argument-1 must be greater than or equal to -1 and less than or equal to +1. 
                     	 
                  
  
               
 
               
              
            
            
               Returned Values
 
               	  
                
                  	 
                  - The returned value is the approximation of the arccosine of argument-1 and is greater than or equal to zero and less than
                     or equal to pi. 
                     		
                     
Note: Conversion factors from radians to degrees and Gon (grad) are specified in the section 
                        		  Trigonometric Functions. 
                        		
                     
 
                     	 
                    
                  	 
                  - Floating-point format is used for numeric non-integer results.