Saturday, August 19, 2017

Eclipse and HHC 2017

Eclipse

On August 21, 2017 there will be a solar eclipse.  Totality (where the moon completely covers the sun) will occur in the northern part of Earth, including some of the United States.  

If you can't get to an area where you can see the eclipse, I believe it is possible to watch it online.  

For more information, click here:
https://eclipse2017.nasa.gov/

HHC 2017

I am looking foward to the HHC 2017 (HP Handheld Conference) in Nashville in September.  I will be speaking on the HP 12C calculator, one of the stables of the HP calculators.

For more information, click here:
http://hhuc.us/2017/

Stay safe, stay sane, and I will probably speak with you by the end of August!

Eddie

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.

Eclipse and HHC 2017

Eclipse On August 21, 2017 there will be a solar eclipse.  Totality (where the moon completely covers the sun) will occur in the northern...