HP 39g Graphing Calculator - Manual (Page 145)

The symbols for differentiation and integration are available
directly form the keyboard— | d / d x | and I respectively—as
well as from the MATH menu.
d Differentiates expression with respect to the variable of
differentiation. From the command line, use a formal name
(SI, etc.) for a non-numeric result. See “Finding derivatives”
on page 10-23.
dvariable{expression)
Example
Ssl (sl^+3*sl) returns 2*sl+3
f Integrates expression from lower to upper limits with respect
to the variable of integration. To find the definite integral,
both limits must have numeric values (that is, be numbers or
real variables). To find the indefinite integral, one of the limits
must be a formal variable (si, etc.).
I (lower,upper,expression,variable)
See “Using formal variables” on page 10-22 for further
details.
Example
Calculus functions
TAYLOR
f ( 0, si, 2*X+3 , X) I ENTER
I
gHSOH I ENTER
I
finds the
indefinite result 3*sl+2* ( s l ' ' 2 / 2 )
See “To find the indefinite integral using formal
variables” on page 10-25 for more information on
finding indefinite integrals.
Calculates the ijth order Taylor polynomial of expression at
the point where the given variable =
0
.
TAYhOR(expression,variable,n)
Example
TAYLOR (1 + s i n ( s l ) ^ , s l , 5 ) with Radians angle
measure and Fraction number format (set in MODES)
returns l + s l ^ 2 - l / 3 * s l " ' 4 .
Using mathematical functions 10-7