HP 15c Collector's Edition

228 Appendix D: A Detailed Look at _
Solution: The equation for the shear stress for x between 0 and 10 is
more efficiently programmed after rewriting it using Horner’s method:
Q
= (3
x
−
45)
x
2
+ 350
for 0 <
x
<
10.
Keystrokes
Display
| ¥
000-
Program mode.
´ b 2
001-42,21, 2
1 002- 1
Test for x range.
0
003- 0
| £
004- 43 10
t 9
005- 22 9
Branch for x ≥ 10.
| `
006- 43 35
3
007- 3
*
008- 20
3x.
4
009- 4
5 010- 5
-
011- 30
(3x − 45).
*
012- 20
*
013- 20
(3x − 45)x
2
.
3 014- 3
5
015- 5
0 016- 0
+
017- 40
(3x − 45)x
2
+ 350.
| n
018- 43 32
End subroutine.
´ b 9
019-42,21, 9
Subroutine for x ≥ 10.
“
020- 26
3
021- 3
10
3
= 1000.
| n
022- 43 32
End subroutine.
Execute _ using initial estimates of 7 and 14 to start at the outer
end of the beam and search for a point of zero shear stress.