HP 39g+, User Manual

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Solve aplet 7-5
Use an initial guess
You can usually obtain a faster and more accurate
solution if you supply an estimated value for the unknown
variable
before pressing . Solve starts looking for
a solution at the initial guess.
Before plotting, make sure the unknown variable is
highlighted in the numeric view. Plot the equation to help
you select an initial guess when you don’t know the range
in which to look for the solution. See “Plotting to find
guesses” on page 7-7 for further information.
H I N T An initial guess is especially important in the case of a
curve that could have more than one solution. In this case,
only the solution closest to the initial guess is returned.
Number format
You can change the number format for the Solve aplet in
the Numeric Setup view. The options are the same as in
HOME MODES: Standard, Fixed, Scientific, and
Engineering. For the latter three, you also specify how
many digits of accuracy you want. See “Mode settings”
on page 1-10 for more information.
You might find it handy to set a different number format
for the Solve aplet if, for example, you define equations
to solve for the value of money. A number format of
Fixed 2
would be appropriate in this case.
Clears highlighted variable to zero or
deletes current character in edit line,
if edit line is active.
CLEAR
Resets all variable values to zero or
clears the edit line, if cursor is in edit
line.
Key Meaning (Continued)