HP 39g+ Graphing manual Use an initial guess

Key	Meaning (Continued)
	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.

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.

Solve aplet 7-5