this post was submitted on 27 Apr 2025
827 points (98.9% liked)

Funny

9279 readers
1205 users here now

General rules:

Exceptions may be made at the discretion of the mods.

founded 2 years ago
MODERATORS
 
top 50 comments
sorted by: hot top controversial new old
[–] [email protected] 2 points 8 hours ago
[–] [email protected] 73 points 1 day ago* (last edited 1 day ago) (7 children)

you can trucate it and it still only a slightly worse approximation:

987/123 = 8.024

98/12 = 8.167

9/1 = 9.000

The last one is pretty bad you should probably not use it

[–] [email protected] 32 points 1 day ago
[–] [email protected] 4 points 19 hours ago

16/2 is an almost exact replacement for 8. OP's name includes Fermat, and so he's probably smarter than me though.

[–] [email protected] 35 points 1 day ago (1 children)

9/1 is approximately 8, for extremely large values of 8.

[–] [email protected] 4 points 1 day ago

Hello, fellow old nerd.

[–] [email protected] 7 points 1 day ago (1 children)

Nah, the engineer probably designed it with a safety factor. You could probably even go 9/0 and be perfectly safe ;)

[–] [email protected] 2 points 1 day ago (1 children)

what about 8/1 would that be save?

[–] [email protected] 3 points 22 hours ago

Don't cut corners

[–] [email protected] 12 points 1 day ago

Have you considered running for Indiana governor? You have the right mindset.

https://en.wikipedia.org/wiki/Indiana_pi_bill

[–] [email protected] 17 points 1 day ago (2 children)

For that last one, how bad are we talking? I need to know soon, I have some important banking software I need to develop.

[–] [email protected] 13 points 1 day ago

I wouldn't use it for precise calculations at NASA, but for banking stuff I think it would be fine :)

[–] [email protected] 3 points 1 day ago

It depends on the scale of the thing you're using it for.

[–] [email protected] 8 points 1 day ago* (last edited 1 day ago)

By the way guys, a very similar approximation for 8, which also starts at 9.000 for n=1, but quickly gets much closer to 8 for increasing n, is:

exp{-2(n-1)} + 8

It approaches 8 about as fast as the above method but this one has a simple formula that is usable in python etc.

[–] [email protected] 10 points 1 day ago (1 children)

You may call it an approxim8ion

[–] [email protected] 2 points 21 hours ago

gr8 m8, I r8 8/8

[–] [email protected] 21 points 1 day ago (2 children)

987654312÷123456789

Change the 21 at the end of the first number to 12 and its perfect. It was only ever 9 away.

[–] [email protected] 12 points 1 day ago
[–] [email protected] 9 points 1 day ago* (last edited 19 hours ago)

Witch! Begone foul demon, and take your dark sorcery with you!

[–] [email protected] 75 points 1 day ago (9 children)

Shit like this makes me realise why people become mathematicians. You just play around with numbers and find funny facts about them.

[–] [email protected] 14 points 1 day ago (1 children)

I myself once learned 380 digits of π, when I was a crazy high-school kid. My never-attained ambition was to reach the spot, 762 digits out in the decimal expansion, where it goes "999999", so that I could recite it out loud, come to those six 9s, and then impishly say, "and so on!"

—Douglas Hofstadter

[–] [email protected] 5 points 1 day ago (1 children)

That would be an amazing party trick.

[–] [email protected] 4 points 1 day ago (5 children)

Actually come to think of it, even more amazing in the age of smart phones, when it's possible to easily verify to numbers you're reciting.

load more comments (5 replies)
[–] [email protected] 49 points 1 day ago* (last edited 1 day ago) (1 children)

So, years ago in college in Linear Algebra our professor said to us to study about idempotent matrices. So I checked out that wiki page and saw the example for 2x2 matrix, that are composed by the numbers 3, -6, 1 and -2. And I was like wait a second, 3×-2=-6 there's no way they are not relationship there, so I started trying other numbers, and found and proved (using induction) that any n, -n(n-1), 1, -(n-1) is an idempotent matrix. At the test there were no questions about that, and I was short of 0.5 poits to pass the class without having to present a final exam and I told my professor that I spent a lot of time learning that and that even discovered something and proved he pass me the chart and asked me to proved it, after that he gave the missing points. Was really good.

[–] [email protected] 5 points 1 day ago (1 children)

You need to put the name inside the brackets and the link inside the parentheses.

idempotent matrices

[–] [email protected] 3 points 1 day ago
[–] [email protected] 7 points 1 day ago

Then you try to figure out why they do be like that

load more comments (6 replies)
[–] [email protected] 45 points 1 day ago (7 children)

gonna need this in every base

I'll start with base 2:

1/1 = 1

[–] [email protected] 16 points 1 day ago

Base 3:

21 / 12 = 1.1012101210121012

[–] [email protected] 9 points 1 day ago (1 children)

gonna need this in every base

...all of them?

[–] [email protected] 3 points 1 day ago

for great justice

load more comments (5 replies)
[–] [email protected] 13 points 1 day ago

9876543210987654321 / 1234567890123456789 = 8,0000000729000

[–] [email protected] 32 points 1 day ago

I just noticed what the numbers are. It really is easy to memorize. So convenient.

[–] [email protected] 20 points 1 day ago

The funniest part is that some people will never understand the absolute crusade that some mathematicians might fight over this one day

[–] [email protected] 4 points 1 day ago* (last edited 1 day ago) (2 children)

It contains the number 8 though. So how is that useful

[–] [email protected] 4 points 1 day ago

Well, simple. Jest substitute that 8 with the above approximation.

[–] [email protected] 2 points 1 day ago

It contains the numbers 8x10^7 and 8x10^1, but not 8x10^0

[–] [email protected] 16 points 1 day ago (2 children)

I wonder if there’s a related infinite sequence which converges on 8?

[–] [email protected] 20 points 1 day ago (4 children)

This sequence approximates an integer to arbitrary precision, not 8 specifically though, and never perfectly.

I tried it out using other bases, and the rule seems to be that doing this in base n results in n-2 with remainder n-1. So it doesn't ever actually converge, but the remainder becomes small very fast.

load more comments (4 replies)
[–] [email protected] 4 points 1 day ago

(n * 8 + 1) / n

load more comments
view more: next ›