this post was submitted on 11 Jan 2024
46 points (100.0% liked)

4chan

4719 readers
4 users here now

Greentexts, memes, everything 4chan.

founded 2 years ago
MODERATORS
 
top 8 comments
sorted by: hot top controversial new old
[–] [email protected] 2 points 1 year ago

The snark in that first reply is glorious.

[–] [email protected] 9 points 1 year ago* (last edited 1 year ago) (2 children)

That's surprisingly accurate, as people here are highlighting (it makes geometrical sense when dealing with complex numbers).

My nephew once asked me this question. The way that I explained it was like this:

  • the friend of my friend is my friend; (+1)*(+1) = (+1)
  • the enemy of my friend is my enemy; (+1)*(-1) = (-1)
  • the friend of my enemy is my enemy; (-1)*(+1) = (-1)
  • the enemy of my enemy is my friend; (-1)*(-1) = (+1)

It's a different analogy but it makes intuitive sense, even for kids. And it works nice as mnemonic too.

[–] [email protected] 1 points 1 year ago

It’s a different analogy but it makes intuitive sense, even for kids.

Its good maths but terrible realpolitick.

[–] [email protected] 1 points 1 year ago

I teach maths and one of the analogies is use is watching a film of someone walking forwards and backwards. If you play the film forwards (multiplying by positive), you can see the person walking forwards and backwards as normal. If you play the film backwards (multiplying by negative) you see the opposite. So multiplying by negative reverses whatever was happening before. Hard to put into words but the visuals (hopefully) seem to explain it well enough.

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

Lmao not gonna lie, this would be a very intuitive way of teaching a kid negative values.

[–] [email protected] 1 points 1 year ago (1 children)

How is multiplying akin to rotating?

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

Fun fact: exponents and multiplication DO work like rotation ... in the complex domain (numbers with their imaginary component). It's not a pure rotation unless it's scalar, but it's neat.

I know I explained that the worst ever, but 3blue1brown on YT talks about it and many other advanced math concepts in a lovely intuitive way.

[–] [email protected] 1 points 1 year ago

“It absolutely, definitely makes sense”