HP 40gs User Manual page 292

Part 4
Part 5
16-18
y' t ( )
To calculate
by typing: DERVX(Y(t)).
Pressing returns:
Press again to
simplify the result:
Select FACTOR and press
.
You can now define the
y' t ( )
function (in the same
way that you defined
x' t ( )
).
To show the variations of
x t ( ) y t ( )
and on the same graph.
The independent variable must be t which it should be as
a result of the previous calculations. (You can check this
by pressing
Type X(t) in the Equation
Writer and press
The corresponding
expression is displayed.
Now press
Function, press
select F1 as the destination and press
Now do the same thing with Y(t), making F2 the
destination.
To graph the functions, quit
CAS (by pressing
choose the Function
aplet, and check F1 and
F2.
, begin
x t ( ) y t ( )
and
.)
.
, select
,
),
, we will trace
.
Step-by-Step Examples