Monday, January 25, 2016

Video: Combinations vs Permutations

This short video explains the difference between combinations and permutations.

Link:  https://www.youtube.com/watch?v=Pj3sowlVbec



Eddie

Change of Plans

Apparently, someone on YouTube, maybe the company itself, doesn't like algebra. Who knew talking about the F.O.I.L. method was so offensive? I am appealing the decision.

For the time being, I will probably cease making videos until this matter is resolved (I expect it to be in my favor, but who knows). 

Eddie


Update: YouTube restored my FOIL video and I am back in good standing.  Happy dance!  Eddie

Sunday, January 24, 2016

Math Videos and Update

Sample Slide

Over the next few weeks I am going to working several short math videos that I will post on YouTube.  When each video is completed, I will leave a link to that video on this blog.  

The videos are going to be pretty short covering various topics in mathematics.  

I hope you enjoyed the HP 15C programs posted over the last two weeks.  I plan to continue to post programs for various calculators this year. 


 I thank you for the comments and reviews.  Talk to you next time, and be safe everyone,

Eddie

Thursday, January 14, 2016

HP 15C: Approximate Length of Sunlight During a Day



HP 15C:  Approximate Length of Sunlight During a Day

For the HP 35S version, please click here:


Source: Total Daily Amount of Solar Radiation - HP 67/97 Energy Conservation Pac, December 1978, Author: Hewlett Packard

Instructions:

Y Stack:  Enter the latitude (North as positive, South as negative).  Use the D.MMSS (degrees-minutes-seconds) format

X Stack:  The number of days after March 21.  A 365 day year is assumed, as well as assuming March 21 is the vernal equinox.

Run the program.

This is an approximation.

Program:

Step
Key
Key Code
001
LBL E
42, 21, 5
002
DEG
43, 7
003
.
48
004
9
9
005
8
8
006
5
5
007
6
6
008
*
20
009
SIN
23
010
2
2
011
3
3
012
.
48
013
4
4
014
5
5
015
*
20
016
X<>Y
34
017
>H
43, 2
018
TAN
25
019
X<>Y
34
020
TAN
25
021
CHS
16
022
*
20
023
COS^-1  (ACOS)
43, 32
024
>RAD
42, 3
025
2
2
026
4
4
027
*
20
028
π
43, 26
029
÷
10
030
>H.MS
42, 2
031
RTN
43, 32

Example:

Los Angeles, April 17.  Latitude of 34°03’ N, 27 days after March 21. 
Result:  approximately 12.5735 (12 hours, 57 minutes, 35 seconds)

Sydney, June 21.  Latitude of 33°51’31” S (enter as -33.5131), 92 days after March 21. 
Result:  approximately 9.4439 (9 hours, 44 minutes, 39 seconds)

Rome, September 1.  Latitude of 41°51’ N, 164 days after March 21.
Result:  approximately 12.5323 (12 hours, 53 minutes, 23 seconds)

This blog is property of Edward Shore.  2016


HP 15C: Soderberg’s Equation for Fatigue



HP 15C: Soderberg’s Equation for Fatigue

Source:  Step by Step Solutions for your HP Calculator: Engineering Applications.  HP-32S.  Hewlett Packard.  Corvallis, OR.  1988  pg. 52-54




Equation:

Syp/FS = (Smax + Smin)/2 + K * (Syp/Se) * ((Smax – Smin)/2)

Variables:

R0 = Syp = yield point stress
R1 = Se = endurance stress reversed bending tests
R2 = Smax = maximum applied stress
R3 = Smin = minimum applied stress
R4 = K = stress concentration factor
R5 = FS = factor of safety

Instructions:

Enter the known values in each of the variables.  Enter the number of the variable to be solved in register I ( [ STO ] [ TAN ] (I) ).  To solve, enter a range, and press [ f ] [ ÷ ] (SOLVE), [ e^x ] (B). (*or whatever label you assigned this program to)

 Program:

Step
Key
Key Code
001
LBL B
42, 21, 12
002
STO (i)
44, 24
003
RCL 0
45, 0
004
RCL÷ 5
45, 10, 5
005
RCL 2
45, 2
006
RCL+ 3
45, 40, 3
007
2
2
008
÷
10
009
-
30
010
RCL 2
45, 2
011
RCL- 3
45, 30, 3
012
2
2
013
÷
10
014
RCL* 0
45, 20, 0
015
RCL÷ 1
45, 10, 1
016
RCL* 4
45, 20, 4
017
-
30
018
RTN
43, 32

Example:

Find the yield point (R0) given the following:
R1 = Se = 33,000 psi
R2 = Smax = 20,000 psi
R3 = Smin = 10,000 psi
R4 = K = 1.5
R5 = FS = 2
Store 0 in RI.

Solution:  55,000 psi



This blog is property of Edward Shore.  2016

Next Week... and Plans for October 2017

I'm so excited, can't want for next week's HHC 2017 calculator conference in Nashville!  It is my annual calculator conference ...