-2^2= -4

• polarsnake

  4 Dec 05, 21:19

  Well some of my friends were arguing over -2^2= -4 or =4. Well what do you think? Most importantly, would the teacher mark it wrong or right?
  
  I asked my teacher this very same queation and i stumped him for a while
• dragg

  4 Dec 05, 21:22

  to the power of 2 then the answer should be +4.
  
• polarsnake

  4 Dec 05, 21:23

  Originally posted by dragg:

  to the power of 2 then the answer should be +4.
  

  You press calculator and see
• FireIce

  4 Dec 05, 21:23

  (-2)^2 = 4
  
  - (2)^2 - -4
• hisoka

  4 Dec 05, 21:25

  Originally posted by polarsnake:

  Well some of my friends were arguing over -2^2= -4 or =4. Well what do you think? Most importantly, would the teacher mark it wrong or right?
  
  I asked my teacher this very same queation and i stumped him for a while

  anything squared except for i is positive however, if the notation is as you have typed then the answer is -4 reason being the - is not included in the ^2
• polarsnake

  4 Dec 05, 21:25

  Originally posted by FireIce:

  (-2)^2 = 4
  
  - (2)^2 - -4

  Yea, but when there is no bracket available it becomes quite confusing and misleading hehe...
• *Thank You*

  4 Dec 05, 21:27

  Wow...FI-soh can count de wor~
  
  
• polarsnake

  4 Dec 05, 21:27

  Originally posted by hisoka:

  anything squared except for i is positive however, if the notation is as you have typed then the answer is -4 reason being the - is not included in the ^2

  In my Homework I always encounter this kind of problem, I put answer as 4, my teacher mark correct Now, what would the teacher think if I had put -4 instead? Would he mark it as wrong? I wonder...
• oxford mushroom

  4 Dec 05, 21:28

  Originally posted by polarsnake:

  Yea, but when there is no bracket available it becomes quite confusing and misleading hehe...

  You have a point there...can argue your case if your teacher mark you wrong. Good practice if you intend to take up law in future
• hisoka

  4 Dec 05, 21:29

  Originally posted by polarsnake:

  In my Homework I always encounter this kind of problem, I put 4 my teacher mark correct

  your teacher suks lah where she learn maths one ask her come and see me
• technoboy

  4 Dec 05, 22:59

  4 if the power belongs to the negative as well...
• mystiv

  4 Dec 05, 23:01

  generally, -2^2 will be understood as (-2)^2
• stellazio

  4 Dec 05, 23:03

  depends on whether there is a bracket..
• FadeToBlack

  4 Dec 05, 23:41

  Originally posted by mystiv:

  generally, -2^2 will be understood as (-2)^2

  yes, because generally - ( minus ) belongs to the 2
  If there is no bracket stated, obviously it meant -2 and not -(2).
  
  therefore, answer should be positive 4.
• RETARDED_MORON

  5 Dec 05, 00:38

  Common sensical.
• sgFish

  5 Dec 05, 00:47

  Originally posted by *Thank You*:

  Wow...FI-soh can count de wor~
  
  

  raffles girl hor, don't pray pray
• CoolMyth

  5 Dec 05, 02:33

  Riddle me this:
  
  Consider the case (-2)^2 = 4
  
  What if we "power" both sides by 1/2, ie:
  
  (-2)^[2 * (1/2)] = 4^(1/2)
  
  --> (-2)^1 = 4^(1/2)
  
  --> (-2)^1 = sqrt (4)
  
  --> - 2 = 2
  
  Where is the contradiction?
• kenshin_himura

  5 Dec 05, 02:39

  Originally posted by CoolMyth:

  Riddle me this:
  
  Consider the case (-2)^2 = 4
  
  What if we "power" both sides by 1/2, ie:
  
  (-2)^[2 * (1/2)] = 4^(1/2)
  
  --> (-2)^1 = 4^(1/2)
  
  --> (-2)^1 = sqrt (4)
  --> - 2 = 2
  
  Where is the contradiction?

  (-2)^1 = sqrt (4)
  
  when u root 4 u get +2 or -2 there for there r 2 ans =D both are real roots jsut that one is positive and one is negative root lor.
• kenshin_himura

  5 Dec 05, 02:43

  and un forget when u apply 1/2 to both sides u get +2 and -2 on the other side therefore its tellies so no mistake
• kenshin_himura

  5 Dec 05, 02:46

  actually i have a QS for all if X^2 = 49 then sqrt of X^2 will be +7 and -& but on the left will u get +x and -X. though it is wrong to write it this way i was wondering y?
• CoolMyth

  5 Dec 05, 02:47

  Originally posted by kenshin_himura:

  (-2)^1 = sqrt (4)
  
  when u root 4 u get +2 or -2 there for there r 2 ans =D both are real roots jsut that one is positive and one is negative root lor.

  Now, think about this, what if we say the whole thing is like this:
  
  (-2)^2 = x^2 = 4
  
  --> (-2)^[2*(1/2)] = x = 4^(1/2)
  
  --> (-2)^1 = x = 4^(1/2)
  
  --> (-2)^1 = x = sqrt (4)
  
  --> - 2 = x = 2
  
  By the colored portion in the quote, x = - 2 or 2. But in this case, I have shown that x = - 2 and 2. Is there any contradictions?
• kenshin_himura

  5 Dec 05, 02:49

  and it is quite debatable.. [(-2)^2]^1/2 = -2 however u can also get [4^1/2] = +2 and -2 hmmm weird.. guess -2 wil be the ans as 2 will be N.A haha
• angelfairy

  5 Dec 05, 02:53

  Originally posted by CoolMyth:
  
  
  Now, think about this, what if we say the whole thing is like this:
  
  (-2)^2 = x^2 = 4
  
  --> (-2)^[2*(1/2)] = x = 4^(1/2)
  
  --> (-2)^1 = x = 4^(1/2)
  
  --> (-2)^1 = x = sqrt (4)
  
  --> - 2 = x = 2
  
  By the colored portion in the quote, x = - 2 or 2. But in this case, I have shown that x = - 2 [b]and 2. Is there any contradictions?[/b]

  isnt sqrt(x^2) mod x or |x| cause you wont know if the x was -2 or 2?
• kenshin_himura

  5 Dec 05, 03:16

  Originally posted by CoolMyth:
  
  
  Now, think about this, what if we say the whole thing is like this:
  
  (-2)^2 = x^2 = 4
  
  --> (-2)^[2*(1/2)] = x = 4^(1/2)
  
  --> (-2)^1 = x = 4^(1/2)
  
  --> (-2)^1 = x = sqrt (4)
  
  --> - 2 = x = 2
  
  By the colored portion in the quote, x = - 2 or 2. But in this case, I have shown that x = - 2 [b]and 2. Is there any contradictions?[/b]

  opps sorrie
  typo shd be and not or hahathink and type differently
• CoolMyth

  5 Dec 05, 03:31

  Originally posted by kenshin_himura:

  opps sorrie
  typo shd be and not or hahathink and type differently

  Do you know the meaning of "and" and "or"?
  
  In Maths, there is a BIG difference.