On Sat, 24 Jan 2009 09:31:04 -0800 (PST), joeu2004
wrote:

On Jan 24, 5:32*am, Ron Rosenfeld wrote:
If you were to graph NPV vs discount rate for the
above series of cash flows, you would see that the
graph crosses the 0 line at two points -- a highly
negative and a highly positive rate.

How did you use a "highly negative" discount rate?

The terms of the NPV formula include the factor 1/(1+i)^n. If i =
-100%, the factor is incalculable. If i < -100%, we can calculate the
factor only for even-numbered cash flows.

I just put a negative value into the NPV formula. I believe others have posted
a better analysis of the problem than my feeble (and inaccurate) attempt.
--ron