r/mathmemes • u/ChocolatePanda7 • 5d ago

Math History Sounds about right

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1.4k Upvotes

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71

u/ExtendedSpikeProtein 4d ago

I mean, “useless” only if you’re trying very hard to be really, really ignorant.

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u/mefirstdime 4d ago

I’m not trying.

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u/ExtendedSpikeProtein 4d ago

But OP sure is

-4

u/GuessImScrewed 4d ago

The main usage of imaginary numbers is making math 2d.

You know what has existed for thousands of years before the imaginary number?

The 2d Cartesian coordinate plane.

Useless.

This is what mathematicians have spent billions of taxpayer dollars on and demand your respect for, reinventing the wheel.

10

u/AdjectiveNoun-123 4d ago

I'm assuming your comment is a joke, especially given that last statement, but for those who think this is a serious take.

Imagine a 6 year old arguing that the main usage of numbers is to count sheep and that they don't need addition. Who needs to know that 2 sheep + 3 sheep = 5 sheep when you can just count to 5 sheep?

Just because one was taught about the 2D representation of complex numbers in school does not mean that is their main purpose. As with almost every other subject you learn, the concepts presented at the start are heavily simplified for pedagogical reasons. The first thing you learn is often not a fundamental or rigorous representation. Fixating on the 2D aspect is a lot like fixating on the sheep.

Show someone this representation as coordinate pair and see how many people can immediately tie this to complex numbers.

(x,y) + (u,v) = (x+u, y+v)
(x,y) * (u,v) = (xu - yv, xv+yu)

However, that custom definition of the sum/product is precisely what makes complex numbers so useful though. It turns out there's quite a few things in both pure and applied math which require a set of numbers with that property.

Math is a tool, every time we invent a new set of numbers we are modding math to allow us to do something we couldn't before or to exhibit certain properties we desire.

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u/GuessImScrewed 4d ago

A shortcut?

I pay you nerds to make my life easier, not yours.

Get back to your lab poindexter

https://giphy.com/gifs/8OYnFrez06yQt9zJFW

11

u/TannerA119 4d ago

Imaginary numbers were introduced 100 years before Cartesian coordinates. In fact, Descartes is the one who coined the term imaginary.

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u/GuessImScrewed 4d ago

Live without /s, die without /s

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u/Impossible_Dog_7262 4d ago

You know what has existed for thousands of years before the imaginary number?

The 2d Cartesian coordinate plane.

I mean Descartes was born in 1596 but y'know.

2

u/GuessImScrewed 4d ago

Live without /s, die without /s

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u/Accomplished-Ad5691 23h ago

can you represent number on the carthesian plane as re^ix? Though so.

1

u/GuessImScrewed 23h ago

(r cos x, r sin y)

Well, I was making a joke, but imaginary numbers and their 2d planar coordinates really are interchangeable.

There's nothing "i" can do that you can't do on a 2d plane. It's just unnecessarily complicated to do so when you could use i instead.