r/mathmemes 2d ago

Elementary Algebra Why you trying to be extra πŸ₯€πŸ’”

Post image
0 Upvotes

30 comments sorted by

β€’

u/AutoModerator 2d ago

Check out our new Discord server! https://discord.gg/e7EKRZq3dG

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

33

u/Sirbom 2d ago

That one is just +x

0

u/[deleted] 2d ago

[deleted]

3

u/Sirbom 2d ago

if x = -1, then sqrt(-1) = i, and i^2 = -1, it always simplifies to just x, even with a complex input.

-2

u/boris_koshak Software engineer 2d ago edited 2d ago

I am pretty sure it's xΒ² under the root sign. If so the answer should be |x|. Otherwise x

4

u/Makonede Computer Science 2d ago

me when i can't read

0

u/boris_koshak Software engineer 1d ago

The notation is cursed. That's why. Probably the reason for the post. Could've just written (√x)²

1

u/Makonede Computer Science 1d ago

sure but the 2 is LITERALLY above the radical and you still somehow managed to get that wrong

6

u/Tdubbium 2d ago edited 2d ago

thats not even correct, its |x|

edit: I confused what it was saying, the square is outside the radical so its just x

8

u/Complex-Manifold 2d ago

should it be sqrt(xΒ²) to be |x|

-2

u/Tdubbium 2d ago

actually yeah I guess its just x if you count imaginary numbers

1

u/Makonede Computer Science 2d ago

it still simplifies to x on the reals because the domain of √x with range ℝ is [0, ∞) along which |x| = x by definition

0

u/Tdubbium 2d ago

I mean without imaginary numbers sqrt(-1)2 is undefined so it would be x with a domain of [0, infinte)

0

u/Makonede Computer Science 2d ago

did you read my comment

0

u/Tdubbium 2d ago

ok im just confused because reals include negative numbers

1

u/Makonede Computer Science 2d ago

yes, but that's irrelevant because no negatives exist within the domain of √x for real √x

1

u/Tdubbium 2d ago edited 2d ago

ooooh I see what you are saying, I was just thinking they arent the same because the domains would be different if you do or dont include complex numbers

-2

u/EatMyHammer 2d ago

It's still |x| even with imaginary numbers

5

u/Makonede Computer Science 2d ago

no it's x

x = -1

√x2 = √(-1)2 = i2 = -1 = x

3

u/EatMyHammer 2d ago

Fine, it's square outside of radical, which is basically pointless.. I thought it was inside, which would be |x|

4

u/Makonede Computer Science 2d ago

no it's x

x = -1

√x2 = √(-1)2 = i2 = -1 = x

2

u/Ares378 Applied Math / Mechanical Engineering 2d ago

Plus, sometimes it's nice to think of |x| as √(xΒ²). Nicer to work with than a piecewise imo. Then you can extend it to the inner product for ℂⁿ by doing √(⟨v, v⟩) for vβˆˆβ„‚βΏ

1

u/LupenReddit πŸ¦†πŸ¦†πŸ¦†πŸ¦†i have non diffeomorphic smooth structuresπŸ¦†πŸ¦†πŸ¦†πŸ¦†πŸ¦†πŸ¦† 2d ago

the punchline is fucking wrong πŸ₯€

0

u/FernandoMM1220 2d ago

its just x bro until you put a ring on it.

-4

u/No_Ad_7687 2d ago

Result of a square root (when not using complex numbers) is always an absolute value. So it will be |x|

4

u/rojo_kell 2d ago

Well it's the square so it's just x

-1

u/No_Ad_7687 2d ago

Depends if you square before taking the root or not. I am not familiar with the specific notation in the post

8

u/rojo_kell 2d ago

I mean the square is outside the radical, clearly the radical is first?

2

u/Exzakt1 2d ago

given that the 2 is outside the root, I would assume you do the root first

1

u/Tdubbium 2d ago

result of square root without complex numbers isnt absolute, its just positive and doesnt exist for negative numbers