Sunday, August 13, 2017

Casio fx-3650p and HP 21S: The Intersection Point of a Quadrilateral

Casio fx-3650p and HP 21S: The Intersection Point of a Quadrilateral

Introduction

This program calculates the coordinates of the center of quadrilateral.  For the derivation, please see this link:  http://edspi31415.blogspot.com/2017/08/geometry-intersection-point-of.html


Casio fx-3650P

See the diagram below. 



Due to the lack of variable available, 7, the program asks for A, B, C, and D twice.  Most of my programs asks for the inputs, then executes calculations.  This program asks for some inputs, does some calculations, then asks for more input, then executes calculations, including replacing variables to make room for further calculations. 

Program (91 steps):

? → A : ? → B : ? → C : ? → D :
(D – B) ÷ (C – A → X :
B – A X → Y :
? → A : ? → B : ? → C : ? → D :
(D – B) ÷ (C – A → C :
B – A C → D :
(D – Y) ÷ (X – C → X
D + C X → Y

HP 21S

See the diagram below.  Input the following points into R0 through R7.



Program (the code and steps should be the same for the HP 20S):

Step
Code
Key
01
61, 41, A
LBL A
02
33
(
03
22, 3
RCL 3
04
65
-
05
22, 1
RCL 1
06
34
)
07
45
÷
08
33
(
09
22, 2
RCL 2
10
65
-
11
22, 0
RCL 0
12
74
=
13
21, 8
RCL 8
14
55
*
15
22, 0
RCL 0
16
32
+/-
17
75
+
18
22, 1
RCL 1
19
74
=
20
21, 0
STO 9
21
33
(
22
22, 7
RCL 7
23
65
-
24
22, 5
RCL 5
25
34
)
26
45
÷
27
33
(
28
22, 6
RCL 6
29
65
-
30
22, 4
RCL 4
31
34
)
32
74
=
33
21, 6
STO 6
34
55
*
35
22, 4
RCL 4
36
32
+/-
37
75
+
38
22, 5
RCL 5
39
74
=
40
21, 7
STO 7
41
33
(
42
22, 7
RCL 7
43
65
-
44
22, 9
RCL 9
45
34
)
46
45
÷
47
33
(
48
22, 8
RCL 8
49
65
-
50
22, 6
RCL 6
51
74
=
52
21, 8
STO 8
53
26
R/S
54
55
*
55
22, 6
RCL 6
56
75
+
57
22, 7
RCL 7
58
74
=
59
21, 9
STO 9
60
61, 26
RTN


Variables – HP 21S: 

Register
Input
Output
R0
A1

R1
B1

R2
C1

R3
D1

R4
A2

R5
B2

R6
C2
C’
R7
D2
D’
R8

X
R9

Y

Example



From top-left hand corner clockwise:  (-1, 4), (4, 6), (5, -1), (0, 0)

Results:
X = 1.357142857
Y = 2.035714286

Eddie


This blog is property of Edward Shore, 2017.