The ANNUITY function (annuity immediate) returns a numeric value that approximates the ratio of an annuity paid at the end
                  of each period for the number of periods specified by argument-2 to an initial investment of one. Interest is earned at the
                  rate specified by argument-1 and is applied at the end of the period, before the payment. 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 zero. 
                     	 
                  
- Argument-2 must be a positive integer. 
                     	 
                  
  
            
            
               Returned Values
 
               	  
                
                  	 
                  - When the value of argument-1 is zero, the value of the function is the approximation of: 
                     		
                     1 / argument-2 
                        		
                      
- When the value of argument-1 is not zero, the value of the function is the approximation of: 
                     		
                     argument-1 / (1 - (1 + argument-1) ** (- argument-2)) 
                        		
                      
- Floating-point format is used for numeric non-integer results.