Plus42 Equations, Preview Release

[Albert Chan]

(06-17-2022 11:32 AM)Vincent Weber Wrote:  It is not THAT wrong, it is a sign issue, more a philosophical thing, do you make money or pay some.
If you know what you are doing and how to interpret the results, then both ways are fine.

Sign is important !

Some situations, even signed zero is important !
Much Ado About Nothing's Sign Bit, by W. Kahan

With the right sign, if we follow the math, we get the right answer.
And, it signal problems, without extensive "intepretation"

Doing the same amortization problem on TI BA-35 Solar (loan-convention)

PMT 01-12: ΣINT = 756.35, ΣPRN = 5413.33
PMT 13-24: ΣINT = 189.50, ΣPRN = 5980.18
PMT 25-36: ΣINT = -436.70, ΣPRN = 6606.38

Every year, ΣINT + ΣPRN = 12*PMT = 12*514.14 = 6169.68