Suppose I have three parameters - Original Principal = 500, terms(in months) = 12, and Interest rate = 8.25. I want write a function that produce the following below. For that monthly payment, I can code it.
For example. P = 500, i = (8.25/100)/12, and n = 12 (months).
monthlypayment = P [(i(1 + i)^n / ((1 + i)^n) - 1]
43.55 = monthlypayment.
But what about Cumulative principal and cumulative interest rate? (Note: those aren't negative numbers, just - in front).