HP HP-15C - Page 103

Section 9: Subroutines 103
MAIN PROGRAM
|¥
´ CLEAR M
(Not programmable.)
000-
001- ´ b 9
Start main program.
002- | R
Radians mode.
003- O 0
Stores x
2
in R
0
.
004- ®
Brings x
1
into X; x
2
into Y.
005- O - 0
(x
2
- x
1
) in R
0
.
006- G .3
x
1
.
Return from s
007- “
- y
1
.
008- ®
Brings x
2
into X-register.
009- G .3
Transfer to subroutine with x
2
.

010- +
y
2
- y
1
.
011- l ÷ 0
Recalls (x
2
– x
1
) from R
0
and
calculates (y
2
- y
1
)/(x
2
- x
1
).
012- | n
Program end (return to line 000).
SUBROUTINE
013- ´ b .3
Start subroutine .3.
014- | x
x
2
.
015- | K
Recall x.
016- [
sin x.
017- -
x
2
 sin x, which equals y.
018- | n
Return to origin in main program.
Calculate the slope for the following values of x
1
and x
2
: 0.52, 1.25; -1, 1;
0.81, 0.98. Remember to use G 9 (rather than ´ 9) when addressing a
routine with a digit label.
Answers: 1.1507; -0.8415; 1.1652.