Sunday, May 13, 2018


May 13, 2018 Sunday

Bedtime Story 


Note E of Ada Lovelace - Part 4


Tonight we shall continue with the Note E of Ada Lovelace where she is describing the mechanics of the multiplication operation (A + A1cosθ + A2cos2θ + A3cos3θ…).(B + B1cosθ).

As I explained to you last night, it is rather simple and the product will appear as:

BA + BA1cosθ + BA2cos2θ + BA3cos3θ…
        B1Acosθ + B1A1cosθ.cosθ + B1A2cos2θ.cosθ + B1A3cos3θ.cosθ…

So let us see how the Engine will handle them by placing them in different variable columns:



 


The variable belonging to each coefficient is written below it, as we have done in the diagram, by way of memorandum.

The only further reduction which is at first apparently possible in the preceding result, would be the addition of V21 to V31 (in which case B1A should be effaced from V31).

The whole operations from the beginning would then be-

First series of            Second series of      Third series, which
Operations                Operations              Contains only one
                                                             (final) Operation

1V10x1V0=1V20    1V11x1V0=1V31      1V21x1V31=2V21,
                                                    And V31 becomes=0

1V10x1V1=1V21    1V11x1V1=1V32

1V10x1V2=1V22    1V11x1V2=1V33

1V10x1V3=1V23   1V11x1V3=1V34

We do not enter into the same detail of every step of the processes as in the examples of Notes D and G, thinking it unnecessary and tedious to do so.

The reader will remember the meaning and use of the upper and lower indices, etc, as before explained.

To proceed: we know that

  

\cos n\theta\cdot\cos\theta = \frac{1}{2}\cos \overline{n+1}\theta +\frac{1}{2}\overline{n-1}\theta                         (3)

               
Consequently, a slight examination of the second line of (2) will show that by making the proper substitutions, (2) will become

 

These coefficients should respectively appear on

V20           V21              V22                V23                V24   

Stay tuned to the voice of an average story storytelling chimpanzee or login at http://panarrans.blogspot.com
                              
Good night mon ami and my fellow cousin ape.
                           
  
                

             












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Another great educator and a teacher that I am aware of is Professor Subhashish Chattopadhyay in Bangalore, India.

While I narrate stories, Professor Subhashish an electronic engineer and a former professor at BARC, does and teaches real mathematics and physics.

He started the participation of Indian students at the International Physics Olympiad.

Do visit him here:


All his books can be downloaded for free through this link:


For edutainment and English education of your children, I recommend this large collection of Halloween Songs for Kids:



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