« previous next »
Pages: [1] 2   Go Down

Author Topic: Imaginary Numbers Question  (Read 9933 times)

0 Members and 1 Guest are viewing this topic.

Offline Munchor

  • LV13 Extreme Addict (Next: 9001)
  • *************
  • Posts: 6199
  • Rating: +295/-121
  • Code Recycler
    • View Profile
Imaginary Numbers Question
« on: February 09, 2011, 04:22:26 pm »
No, I'm not asking you to tell me how they work and general stuff.

But the other day my teacher said:

x²>0

And I thought... Hm, any number ² will be bigger than 0, since all squared numbers are positive. However, I just checked:

Code: [Select]
>>> 0**2
0
>>>

And it seems, 0² will be 0, so x²>=0.

What I want to know is if any imaginary number when squared will be minor than 0. Thanks.
Logged

Offline AngelFish

  • Is this my custom title?
  • Administrator
  • LV12 Extreme Poster (Next: 5000)
  • ************
  • Posts: 3242
  • Rating: +270/-27
  • I'm a Fishbot
    • View Profile
Re: Imaginary Numbers Question
« Reply #1 on: February 09, 2011, 04:25:23 pm »
Any purely imaginary number squared will be a negative number. X2>0 is only true for numbers along the real line. Along the imaginary line, numbers like i2 (which equals -1) are not necessarily greater than 0.
Logged
∂²Ψ    -(2m(V(x)-E)Ψ
---  = -------------
∂x²        ℏ²Ψ

Offline ztrumpet

  • The Rarely Active One
  • CoT Emeritus
  • LV13 Extreme Addict (Next: 9001)
  • *
  • Posts: 5712
  • Rating: +364/-4
  • If you see this, send me a PM. Just for fun.
    • View Profile
Re: Imaginary Numbers Question
« Reply #2 on: February 09, 2011, 04:27:35 pm »
Well, the definition of i is "the square root of negative one", so if you did i2, you'd get -1.  Another example: 3i2=-3

You can check this on your calculator by hitting [mode] and changing to to a+bi. :)

Quote from: Scout on February 09, 2011, 04:22:26 pm
And it seems, 0² will be 0, so x²>=0.
Correct.  I believe what your teacher meant to say was "any non-zero number squared will be greater than zero." :D
Logged

Offline Munchor

  • LV13 Extreme Addict (Next: 9001)
  • *************
  • Posts: 6199
  • Rating: +295/-121
  • Code Recycler
    • View Profile
Re: Imaginary Numbers Question
« Reply #3 on: February 09, 2011, 04:29:12 pm »
Quote from: Qwerty.55 on February 09, 2011, 04:25:23 pm
Any purely imaginary number squared will be a negative number. X2>0 is only true for numbers along the real line. Along the imaginary line, numbers like i2 (which equals -1) are not necessarily greater than 0.

Yes!
* Scout wins.

My teacher wrote this:

x²>0

I immediately shouted "x²>=0". And he said, "Oh thanks *myname*".

Then I said:

"x²>0,x IR"

And then he said "Well, that doesn't really matter".

But it seems it does. Thanks.
Logged

Offline jnesselr

  • King Graphmastur
  • LV11 Super Veteran (Next: 3000)
  • ***********
  • Posts: 2270
  • Rating: +81/-20
  • TAO == epic
    • View Profile
Re: Imaginary Numbers Question
« Reply #4 on: February 09, 2011, 05:44:40 pm »
It does matter, but probably not as far as your class is concerned. ;-)
Logged

Offline Juju

  • Incredibly sexy mare
  • Coder Of Tomorrow
  • LV13 Extreme Addict (Next: 9001)
  • *************
  • Posts: 5730
  • Rating: +500/-19
  • Weird programmer
    • View Profile
    • juju2143's shed
Re: Imaginary Numbers Question
« Reply #5 on: February 09, 2011, 11:08:17 pm »
Yes, usually, teachers don't really want to mess with imaginary numbers unless they are actually teaching you imaginary numbers, so they would always say something like "x² ≥ 0 ∈ ℝ".
Logged

Remember the day the walrus started to fly...

I finally cleared my sig after 4 years you're happy now?
THEGAME
This signature is ridiculously large you've been warned.

The cute mare that used to be in my avatar is Yuki Kagayaki, you can follow her on Facebook and Tumblr.

Offline Munchor

  • LV13 Extreme Addict (Next: 9001)
  • *************
  • Posts: 6199
  • Rating: +295/-121
  • Code Recycler
    • View Profile
Re: Imaginary Numbers Question
« Reply #6 on: February 13, 2011, 10:19:36 am »
Quote from: juju2143 on February 09, 2011, 11:08:17 pm
Yes, usually, teachers don't really want to mess with imaginary numbers unless they are actually teaching you imaginary numbers, so they would always say something like "x² ≥ 0 ∈ ℝ".

Yeah, they just say that, but nobody really asks why it has to be in IR, at least in my class, they only care about maths for tests and grades, not maths as Maths :)
Logged

Offline Happybobjr

  • James Oldiges
  • LV11 Super Veteran (Next: 3000)
  • ***********
  • Posts: 2325
  • Rating: +128/-20
  • Howdy :)
    • View Profile
Re: Imaginary Numbers Question
« Reply #7 on: February 13, 2011, 10:45:17 am »
Quote from: Scout on February 09, 2011, 04:29:12 pm
I immediately shouted "x²>=0". And he said, "Oh thanks *scout".

we all know you're scout...:P
* Happybobjr wins
Logged
School: East Central High School
 
Axe: １.０.0
TI-84 +SE  ||| OS: 2.53 MP (patched) ||| Version: "M"
TI-Nspire    |||  Lent out, and never returned
____________________________________________________________

Offline Munchor

  • LV13 Extreme Addict (Next: 9001)
  • *************
  • Posts: 6199
  • Rating: +295/-121
  • Code Recycler
    • View Profile
Re: Imaginary Numbers Question
« Reply #8 on: February 13, 2011, 10:47:40 am »
Quote from: Happybobjr on February 13, 2011, 10:45:17 am
Quote from: Scout on February 09, 2011, 04:29:12 pm
I immediately shouted "x²>=0". And he said, "Oh thanks *scout".

we all know you're scout...:P
* Happybobjr wins

But nobody here knows my real name xD
Logged

Offline ztrumpet

  • The Rarely Active One
  • CoT Emeritus
  • LV13 Extreme Addict (Next: 9001)
  • *
  • Posts: 5712
  • Rating: +364/-4
  • If you see this, send me a PM. Just for fun.
    • View Profile
Re: Imaginary Numbers Question
« Reply #9 on: February 13, 2011, 10:58:56 am »
Quote from: Scout on February 13, 2011, 10:47:40 am
But nobody here knows my real name xD
Silly David...

* ZTrumpet can haz wins!!! O0
« Last Edit: February 13, 2011, 10:59:12 am by ztrumpet »
Logged
+2/-0 karm for this message

Offline Munchor

  • LV13 Extreme Addict (Next: 9001)
  • *************
  • Posts: 6199
  • Rating: +295/-121
  • Code Recycler
    • View Profile
Re: Imaginary Numbers Question
« Reply #10 on: February 13, 2011, 12:19:00 pm »
Quote from: ztrumpet on February 13, 2011, 10:58:56 am
Quote from: Scout on February 13, 2011, 10:47:40 am
But nobody here knows my real name xD
Silly David...

* ZTrumpet can haz wins!!! O0

?? Sorry, I don't understand you. My real name isn't David Gomes xD

Or is it?
« Last Edit: February 13, 2011, 12:19:21 pm by Scout »
Logged

Offline ruler501

  • Meep
  • LV11 Super Veteran (Next: 3000)
  • ***********
  • Posts: 2475
  • Rating: +66/-9
  • Crazy Programmer
    • View Profile
Re: Imaginary Numbers Question
« Reply #11 on: February 22, 2011, 09:15:44 pm »
I have one question i figured I should just add in here.
Can imaginary numbers be prime? I don't think negative numbers could be prime but I don't know about imaginaries. any help would be appreciated.
Logged
I currently don't do much, but I am a developer for a game you should totally try out called AssaultCube Reloaded download here https://assaultcuber.codeplex.com/
-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GCM/CS/M/S d- s++: a---- C++ UL++ P+ L++ E---- W++ N o? K- w-- o? !M V?
PS+ PE+ Y+ PGP++ t 5? X R tv-- b+++ DI+ D+ G++ e- h! !r y

Offline Xeda112358

  • they/them
  • Moderator
  • LV12 Extreme Poster (Next: 5000)
  • ************
  • Posts: 4704
  • Rating: +719/-6
  • Calc-u-lator, do doo doo do do do.
    • View Profile
Re: Imaginary Numbers Question
« Reply #12 on: February 22, 2011, 09:16:56 pm »
I think prime numbers are described as natural numbers, so they must be integers >0
Logged

Offline ruler501

  • Meep
  • LV11 Super Veteran (Next: 3000)
  • ***********
  • Posts: 2475
  • Rating: +66/-9
  • Crazy Programmer
    • View Profile
Re: Imaginary Numbers Question
« Reply #13 on: February 22, 2011, 09:26:10 pm »
OK thanks for the help I thought that would be the answer
(I'm so happy I'm not completely stupid :D)
Logged
I currently don't do much, but I am a developer for a game you should totally try out called AssaultCube Reloaded download here https://assaultcuber.codeplex.com/
-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GCM/CS/M/S d- s++: a---- C++ UL++ P+ L++ E---- W++ N o? K- w-- o? !M V?
PS+ PE+ Y+ PGP++ t 5? X R tv-- b+++ DI+ D+ G++ e- h! !r y

Offline Xeda112358

  • they/them
  • Moderator
  • LV12 Extreme Poster (Next: 5000)
  • ************
  • Posts: 4704
  • Rating: +719/-6
  • Calc-u-lator, do doo doo do do do.
    • View Profile
Re: Imaginary Numbers Question
« Reply #14 on: February 22, 2011, 09:32:47 pm »
I feel happy that I actually understand what I just typed.
Logged
Pages: [1] 2   Go Up
« previous next »