HP 25 User Manual

80 Programming
volume of a spherical balloon as its diameter increases using
the formula:
Increase in volume = 1167T (d
1
3
-
d
o
3
) ,
where do is the original diameter of the balloon and d, is the new
diameter . If do were entered in the Y -register and d, were keyed
into the X-register, the
problem could be solved manually by
pressing the
keys shown in the left-hand column that follows.
Keys
Display
m;:zm
01
31
[]]
02
03
Ow
03
14 03
Cube the new diameter .
EiD
04
21
[]]
05
03
0
06
14 03
Cube the original diameter.
B
07
41 Subtract the cubes .
m El
08
15 73
0
09
61
Multiply by 7T.
~
10 06
G
11 71
I Divide by 6.
The program keystrokes for this problem are the same. Simply
switch to
PRGM mode PRGM ~RUN and press [§§C] to
clear program memory and display step 00. Then key in the
list
of keys above. The keys are not executed, but are recorded
in program memory steps 01 through II. Verify that each key-
code
is correct as you key in each instruction by checking the
displays s
hown.
(Notice that you had to record the m;:zm key as an instruction
in this program. TheBmm instruction here se par ates the num-
ber 3 that is the second step of the program from the digits for
the new
diameter that you will key in later.)

HP 25 Specifications

General

Power Source	Rechargeable battery pack
Programming Steps	49
Release Year	1975
Functions	Trigonometric, logarithmic, statistical
Type	Scientific
Dimensions	148 x 80 x 14 mm