HP 39g+, User Manual

Page: 72 / 294

3-10 Function aplet
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.
Signed area
Select
Signed area
to find the
numeric integral. (If there are two
or more expressions
checkmarked, then you will be
asked to choose the second
expression from a list that
includes the
x -axis.) Select a
starting point, then move the
cursor to selection ending point.
The result is saved in a variable
named AREA.