Two Incredible Math PDFs

[iacas]

I found two amazing PDFs that I would like to share with you.

https://arxiv.org/pdf/1502.03501.pdf

In this paper, every number from 1 to 1000 is written out using each of the nine digits available and only the five basic functions (+, -, x, /, and powers), plus parentheses for grouping.

For example:

To get the number 422 using only the number 7: 422 = 7 × 7 × 7 + 77 + (7 + 7)/7.

To get the number 814 using only the number 2: 814 = 22 × (2 + 2 + 2)² +22.

https://arxiv.org/pdf/1302.1479.pdf

In this paper, every number from 1 to 11,111 (except 10,958 in ascending order) is created using each digit from 1-9 in both ascending and descending order. For example:

2785 in ascending order = 1 + 23 × 4 × 5 × 6 + 7 + 8 + 9.

5296 in descending order = (98 × 7 + 654 × 3) × 2 × 1.

Pretty nifty, I thought.

[saevel25]

Brain hurts 😉

Yea, that is cool. 

[Edsland]

Reminds me of the commercial where the guys on a ladder as the cleaning guy comes in and starts erasing the guys equation. 

[Carl3]

58 minutes ago, iacas said:

Pretty nifty, I thought.

I am an engineer and not too adverse to math, but for me it has to have a purpose to get me interested. I liked differential equations where it was demonstrated that practical problems could be solved. Even freshman year physics we had the distance, velocity, and acceleration expressed through calculus concepts. 

This is too nerdy for me 😃

[dennyjones]

I like it!

[chilepepper]

And some days I’m counting the strokes it took to complete a hole on my fingers

[p1n9183]

On ‎3‎/‎4‎/‎2019 at 9:52 PM, Carl3 said:

I am an engineer and not too adverse to math, but for me it has to have a purpose to get me interested. I liked differential equations where it was demonstrated that practical problems could be solved. Even freshman year physics we had the distance, velocity, and acceleration expressed through calculus concepts. 

This is too nerdy for me 😃

Same here. This is way too much, and useless at the same time.
The best one was "Estadistica aplicada" or "Applied Statistics". "Physics" or "Física" was great too.