HP 39G

Function aplet 3-9
Access FCN
variables
The FCN variables are contained in the VARS menu.
To access FCN variables in HOME:
>9$56@
$3/(7a
Select Plot FCN
*A,
*k,or*e, to choose a
variable
2.a
To access FCN variable in the Function aplet’s Symbolic
view:
>9$56@
Select Plot FCN
*A,
*k,or*e, to choose a variable
2.a
FCN functions The FCN functions are:
Function Description
Root Select Root to find the root of the
current function nearest the cursor.
If no root is found, but only an
extremum, then the result is labeled
EXTR: instead of ROOT:. (The
root-finder is also used in the Solve
aplet. See also “Interpreting results”
on page 7-6.) The cursor is moved to
the root value on the x-axis and the
resulting x-value is saved in a
variable named ROOT.
Extremum Select Extremum to find the
maximum or minimum of the
current function nearest the cursor.
This displays the coordinate values
and moves the cursor to the
extremum. The resulting value is
saved in a variable named
EXTREMUM.
Slope Select Slope to find the numeric
derivative at the current position of
the cursor. The result is saved in a
variable named SLOPE.