HP 39gs Master Guide

R
R
e
e
f
f
e
e
r
r
r
r
i
i
n
n
g
g
t
t
o
o
o
o
t
t
h
h
e
e
r
r
a
a
p
p
l
l
e
e
t
t
s
s
f
f
r
r
o
o
m
m
t
t
h
h
e
e
H
H
O
O
M
M
E
E
v
v
i
i
e
e
w
w
.
.
Once functions or sequences have been defined in other aplets, they can be referenced in the
HOME view.
e.g. 1 Suppose we use the Function aplet to define
F1(X)=X²-2 and F2(X)=e
X
as shown right.
These functions now become accessible not only from within the
HOME
view but also within any other aplet also. This is shown by the screen
shots below.
The results shown will, of course, depend on your settings in the
MODES
view.
The reason for the
QUOTE(X-2) rather than just X-2, is that using X-2
would tell the calculator to use the value currently stored in memory X,
while
QUOTE(X-2) tells it to use the symbol. The QUOTE function is
available through the
MATH menu under Symbolic (see page 181).
Note: This type of work is actually far more easily done in the
Function aplet, where
QUOTE is not needed and the key does a
better job. See page
64.
e.g. 2 Suppose we use the Sequence aplet to define a sequence
T
with
T
1
= 3, 1
2
= and T
n
= 2 T
n−1
+ T
n−2
.
In the
HOME view, the sequence values can be referred to as easily as
the function values in the previous example.
You could also define a function
F1(X) in the Function aplet and then
refer to this function in the
Solve aplet to find, for example, where
F1(X)=1000.
40

HP 39gs Specifications

General

Type	Scientific
Form factor	Pocket
Product color	Gray
Internal memory	0.256 MB

Weight and Dimensions

Weight	249 g
Dimensions (WxDxH)	187 x 94 x 31 mm