ANNUITY
The ANNUITY function returns a numeric value that approximates the ratio of an annuity paid at the end of each period, for a given number of periods, at a given interest rate, to an initial value of one.
The number of periods is specified by argument-2; the rate of interest is specified by argument-1. For example, if argument-1 is zero and argument-2 is four, the value returned is the approximation of the ratio 1 / 4.
The function type is numeric.
- 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.
When the value of argument-1 is zero, the value returned by 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))