HP HP-28S - BOXR (Ratio of Surface to Volume of a Box)

BOXR (Ratio of Surface to Volume of a Box)
Given the height, width, and length of a box, calculate the ratio of its
surface to its volume.
Arguments Results
3:
height
3:
.~. ,
width 2:
'"" .
1 :
length 1 :
area/volume
Techniques:
• Nested user functions. BOXR is a user function whose defining ex-
pression uses BOXS in its calculation. In
turn, BOXR could be used
to define other user functions.
Recall
that BOXS was defined using h, w, and I as local variables,
and note below that BOXS takes x, y, and z as arguments in the
definition for BOXR. It makes no difference if the local variables in
the two definitions match, or if they don't match, because each set
of local variables is independent of the other. However, it's essential
that local variables be consistent within a single definition.
Program
"* ::< 1;:1 Z
, 80::-(:3 (::< .. '::I .. z::O
. / (::<l'::Ilz::O '
[ENTER [
o BOXR [STO[
Comments
Begin the program.
Create local variables for height,
width, and length. This program
uses x, y, and z, rather than h, w,
and l.
Begin the defining expression
with the user function BOXS.
Divide
by the volume of the box .
End the program.
Put the program on the stack.
Store
the program as BOXR.
28: Programming Examples 245