HP 10bII

More About Calculations
IRR/YR Calculations
"The calculator determines JRR/YR for a set of cash flows using
mathematical formulas that search for the answer. The process
finds a solution by estimating an answer and then using that
estimate to do another calculation. This is called an iterative
process.
In most cases, the calculator finds the desired answer, since there
is usually only onc solution to the calculation. However,
calculating IRR/YR for certain sets of cash flows is more complex.
There may be more than one (or no) mathematical solution to
the problem. In these cases, the calculator displays a message to
help you interpret what has happened.
Possible Outcomes of Calculating IRR/YR
"These are the possible outcomes of an IRR/YR calculation:
= Case 1. The calculator displays a positive answer. This is the only
positive answer. However, one or more negative answers may exist.
m Case 2. The calculator finds a negative answer but a single positive
answer also exists. It displays: Pos Irr Also. To see the negative
answer, press (*) to clear the message. To search for the positive
answer, you must input a guess. (Refer to “Entering a Guess for
IRR/YR,” below). There might also be additional negative answers.
Case 3. The calculator displays a negative answer and no message.
This is the only answer.
в Case 4. The calculator displays the message: Not Found. This
indicates that the calculation is very complex. It might involve more
than onc positive or negative answer, or there may be no solution.
To continue the calculation, you must store a guess (see below).
B: More About Calculations 129