HP HP-25 - Page 84

volume
of
a
spherical
balloon
as
its
diameter
increases
using
the
formula:
Increase in volume = 1/6 7 (d,® - d,?),
where d, is the original diameter of the balloon and ¢, is the new
diameter. If dy 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
01 31
o
N 03
03 14 03 Cube the new diameter.
1
05 03
06 14 03 |Cube the original diameter
Subtract the cubes.
o
"
N
08 15 73
Multiply by 7.
10 06
FHENO0
s
2
oy
11 71 Divide by 6.
The program keystrokes for this problem are the same. Simply
switch to PRGM mode rrov [[[I@~~ and press Bl Prem 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 11. Verify that each key-
code is correct as you key in each instruction by checking the
displays shown.
(Notice that you had to record the key as an instruction
in this program. The instruction here separates 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.)