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

HP Prime and TI-84 Plus: Basic Wheatstone Full Bridge Circuit

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