## skullpatrol 3 years ago Why can you never divide by zero?

1. anonymous

Because the answer would be undefined.

2. skullpatrol

What do you mean?

3. anonymous

because you can then create a bunch of false proofs such as 2=1. Notice the last step of the following false proof is actually just division by zero: a = x [true for some a's and x's] a+a = a+x [add a to both sides] 2a = a+x [a+a = 2a] 2a-2x = a+x-2x [subtract 2x from both sides] 2(a-x) = a+x-2x [2a-2x = 2(a-x)] 2(a-x) = a-x [x-2x = -x] 2 = 1 [divide both sides by a-x]

4. anonymous

Because when you get a smaller and smaller number in the denominator the number gets larger and larger (assuming it is positive) for example 1/0.00001 is much larger than one. If its 1/0 it would be infinitely large following the same trend.

5. zepp

Let c (result) be $$\LARGE \frac{a}{b}$$, if b was 0, then $$\large cb=a$$, we need to find a number $$a$$ that could be the answer to $$c*(0)$$, and for all $$c$$, a would always be 0. In this case, we leave this undefined.

6. anonymous

|dw:1353147793508:dw|

7. skullpatrol

@sirm3d neither

8. anonymous

@skullpatrol so there is no correct answer. any correct answer will be contradicted by the same examples above.

9. anonymous

In abstract algebra, 1 is the multiplicative identity. That means that you can multiply any element by 1 and you get the number back. 4*1 = 4. 876*1=876 etc. It's the unique element that does that. You also want to have 'inverse elements'. Those are numbers that when you multiple them together, you get the identity. For example, the inverse element of 5 is 1/5, because 5 * 1/5 = 1, the identity. In multiplication, when you 'divide' by something, you are actually multiplying by the inverse element of the thing, with respect to multiplication. So when you say 4 / 5 you are actually saying 4 * 1/5. The question is, does 0 have a multiplicative inverse? What that's asking is, is there a number x such that 0 * x = 1? There can't be, because, well, from some other places, we sort of want 0 to be the element such that when you multiply anything by 0, then you get 0. So 0 has no inverse. If it did, then lots of the things from abstract algebra, which lay the foundations for arithmetic, would be violated and no longer work properly.

10. anonymous

(above, where I said 4 * 1/5, what I mean is that you're actually multiplying 4 by the number defined as being 1/5. So in a sense there's actually no division. There's just multiplying, by the correct number)

11. anonymous

So when you say you want to divide by zero, what you mean is that you want to multiply by the number that is the "multiplicative inverse" of 0. And the multiplicative inverse of zero is the number x such that 0 * x = 1, and x * 0 = 1. And it can be thought that if such a number exists, then it would wreck everything.

12. anonymous

|dw:1353148249632:dw| if n is the correct answer, what is n then? it would be more sensible to agree that there is no solution than argue that one answer is "more correct" than the other

13. skullpatrol

How about 0*(1/0) = 1 @scarydoor ?

14. anonymous

well, the 'symbols' like 1/5 and 1/0 still need to be translated back into decimal numbers of some kind. We can represent 1/5 in decimals. What value would 1/0 take? The only two possibilities are -infinity and +infinity, which aren't numbers.

15. anonymous

Also, suppose you decide on some decimal value for 1/0 to take, called x (just some number). Then 1/0 = x. Then 1 = x * 0 = 0. So you have that 1 = 0, which means you're going to have some problems.

16. anonymous

if 1/0 is a number, then $\large 1=0\left( \frac{ 1 }{ 0 } \right)=\frac{ 0 }{ 0 }=\frac{ 0\times5 }{ 0 \times 4 }=\frac{ 0 }{ 0 }\left( \frac{ 5 }{ 4 } \right)=\frac{ 5 }{ 4 }$ so we must agree that $1=\frac{ 5 }{ 4 }= \text{any other number}$

17. anonymous

Even if you had 1/0 = infinity, then you'd have 1 = infinity * 0. There are areas of maths where you have accepted rules to do arithmetic on the symbol infinity, and those rules say that infinity * 0 = 0. So you'd still have 1 = 0. But also, I'm not so sure you'd actually still be able to use the algebraic manipulations I used there, since if you have infinity in the system, then it's no longer really a structure of numbers. It's got some symbols in there too...

18. skullpatrol

If 1/0 = x. Then 1 = x * 0 , but how did you algebraically derive 1 = x*0 from 1/0 =x @scarydoor?

19. anonymous

Well, we said 1/0 is the multiplicative identify of 0. That means (the definition of multiplicative identity) that 0 * 1/0 = 1. So 1/0 = x. (now multiply each side by 0, to get...) 0 * 1/0 = 0 * x (then 0 * 1/0 = 1, so...) 1 = 0 * x. (I wrote the right hand side the other way around, but, don't worry about that... )

20. anonymous

21. anonymous

Also, this might seem weird and unconnected to normal arithmetic that you do. But this is really minimalist algebra, and was really just invented to justify the way that we think arithmetic should work (i.e., we want it to be "sensible"). These are really conservative conventions. Just abstract sounding.

22. anonymous

@skullpatrol what about $\large \frac{ 5 }{ 0 }$ is it five times as many as $\large \frac{1}{0}$

23. hartnn

logically speaking, dividing something with a number 'n' means making 'n' equal parts of that 'something. dividing by 0 means you are not making any parts...so such operation is not defined

24. anonymous

$0\left( \frac{ 5 }{ 0 } \right)=\frac{ 0 }{ 1 }\left( \frac{ 5 }{ 0 } \right)=\frac{ 0 }{ 0 }=1$ because $0\left( \frac{ 1 }{ 0 } \right)=\frac{ 0 }{ 1 }\left( \frac{ 1 }{ 0 } \right)=\frac{ 0 }{ 0 }=1$ since this number must obey the multiplication rule for fractions.

25. skullpatrol

But, you have multiplied both sided of an equation by 0. You have used 0 as a multiplier in transforming an equation, which says the final equation will be satisfied by any number no matter what the equation is. @scarydoor

26. anonymous

Also, try to divide 1 by 0. Divide it by increasingly smaller numbers. 1/(1/2) = 2. 1/(1/3) = 3. 1/(1/4)=4. In general, divide 1 by 1/n, where n is a natural number. 1/n gets ever closer to 0 as n gets increasingly larger. So 1/(1/n) = n. And as n goes to infinity (which means you get closer to the "true" value of 1/0) then 1/(1/n) = infinity. So, eventually you would guess that 1/0 might need to be infinity.

27. anonymous

Oh yeah! Good point skullpatrol. Haha... Well, maybe that part of the explanation why it doesn't work needs some improvement. The other peoples' explanations might be better to look at then.

28. anonymous

(also, above, where I was dividing by natural numbers, you could divide by -n, and then the limit comes to -infinity. So there are two implied values for 1/0, at least for that approach...)

29. anonymous

IF you are right that it is possible to divide by zero, that this division by zero results in some quotient and remainder, can you give an answer that is unassailable by any sound argument? @skullpatrol

30. anonymous

people have struggled with the idea of 0 and infinity for thousands of years. Lots of very smart people didn't know what to do with the complications. There are two good books about it. I read one (the one where reviewers say there is less maths, whichever that is...) and found it to be a very entertaining read on the topic: http://www.amazon.com/Zero-Biography-Dangerous-Charles-Seife/dp/0140296476/ref=sr_1_3?s=books&ie=UTF8&qid=1353150007&sr=1-3&keywords=zero http://www.amazon.com/The-Nothing-that-Is-Natural/dp/0195142373/ref=pd_vtp_b_2

31. anonymous

You might be able to find one of them at a library. They will give you lots more intuition about the development of the idea of 0 (and infinity).

32. skullpatrol

All I'm saying is a lot of Professors give the argument: If a/0=c, then a=0*c. But as we have shown this argument is flawed by the fact that you are using 0 as a multiplier in transforming a/0=c into a=0*c.

33. anonymous

hmn. actually.... coming to think about it, we can multiply each side by zero, right? The reason is that it "should" make both sides equal to zero. (and in fact you can multiply each side by the same number, for any number, and the equality will hold) So actually I'm going back on my reneg, and say that it was fine to multiply both sides by zero.

34. anonymous

The problem is that we have a number (1/0) which we defined so that 0 * 1/0 = 1.

35. anonymous

Can you explain why it shouldn't have been okay to multiply both sides by 0? Or why you think that shouldn't have been allowed? Because if you can be convinced that it was allowed, then that would confirm that we shouldn't be allowed to divide by zero, right?

36. skullpatrol

Also,they are implying that 0*(a/0) = 0*(1/0)*a and then 0*(1/0) = 1 but we know that 0 has no reciprocal because 0 times any number is 0 not 1.

37. anonymous

I don't understand what you're saying.

38. anonymous

the trouble with accepting 1/0 as a number is determining the value of a * (1/0)

39. skullpatrol

You have used 0 as a multiplier in transforming an equation, which says the final equation will be satisfied by any number no matter what the equation is. @scarydoor

40. anonymous

if (1/0) = x, and x is the multiplicative inverse of 0, then... 0 * (1/0) = 0 * x (multiply both sides by 0. (if two numbers are equal, then to multiply them by the same number, they should still be equal) 1 = 0. (since 0 * 1/0 = 1 (left hand side) and 0 * any number = 0 (right hand side) 1=0 is absurd. so the assumption that (1/0) exists and is a real number, must have been wrong. (proof by contradiction).

41. anonymous

by the same assumptions I made in the first line, you could say that... 1/0 = x (then multiply both sides by a to get...) a * 1/0 = a * x (post multiply both sides by 0...) a * (1/0 * 0) = (a * x) * 0 a * 1 = 0 a = 0. This is true for any number a..

42. skullpatrol

Any equality will be satisfied by any real number if you multiply both sides by 0. for example x=5 is only satisfied by 5 but 0*x=0*5 or 0*x=0 is now satisfied by any real number so it is not equivalent to the original equation x=5.

43. anonymous

But to make that claim, you have assumed you can divide by 0! That's the bad link. you said that if you can say 0*x = 0*5, then x must be equal to 5. But how did you get rid of the 0? You must have tried to divide by 0. That's basically what I'm saying in the argument above.

44. anonymous

Are you convinced?

45. skullpatrol

no

46. skullpatrol

I'm saying starting with the original equation x=5 and asking for what values is it satisfied for? The answer is 5, because when we substitute 5 into the original equation we get a true statement 5=5.

47. anonymous

which original equation? I'm not sure where you think the problem is.

48. skullpatrol

Take any equation as your original equation try: 8z=40 the solution set to this equation is {5}.

49. anonymous

That's right.

50. skullpatrol

Now transform that original equation by multiplying both sides by 0.

51. anonymous

I think you're saying that if I now say that 0 * 8z = 0 * 40, then the solution for z is any number. And you think that's a problem because before we said that z = 5.

52. anonymous

The problem is in direction of implication. I can say that if 8z = 40, then 0 * 8z = 0 * 40. But I can't say that if 0 * 8z = 0 * 40 then 8z = 40. Because I'm saying that 0 = 0 means that 8z = 40.

53. skullpatrol

Yes, that is correct. Zero is not allowed as a multiplier in transforming equations.

54. anonymous

It's allowed as a transformation, but the implication is only one way. If it's not zero then I can get back again. but with zero I can't.

55. anonymous

So, before I said that 1/0 = x is an equality. Then I multiply both sides by 0, I'm going in the correct direction for the implication... 1/0 * 0 = x * 0. This equality still holds. Now I use that 1/0 is the identiy of 0, and that x * 0 = 0... 1 = 0.

56. anonymous

What you are trying to do is go in the other direction. But I don't need to go in the other direction, so I don't care that I can't.

57. anonymous

think about this.... 6 = 3 * 2. That's correct. Now multiply both sides by 0. We get that 0 = 0. Can we conclude, from 0 = 0 that 6 = 3 * 2? We can't. Actually this all comes back to the fact that we can't divide by zero, and that's because 0 is the annihilator. If we could divide by zero, then we could go in the backwards direction too.

58. anonymous

Does that make sense?

59. anonymous

If you have x = y, then a * x = a * y for any number a. Now, so long as a is not zero, then 1/a * a * x = 1/a * a * y. Which means that 1 * x = 1 * y. x = y. So you can go both ways. Notice that the only reason you can't go backwards again if a is equal to zero is that you can't divide 1 by zero. (where a = 0, 1/a = 1/0).

60. skullpatrol

I agree :)

61. anonymous

haha, good.

62. anonymous

algebra is fun.

63. skullpatrol

But the definition of equivalent equations is equations that have the same solution set and multiplying both sides by 0 , because 0 is the annihilator. Annihilates all the information with any equation, so it is not allowed.

64. anonymous

it's not allowed if you want to preserve all the information. But I didn't want to, so it didn't matter. I only wanted to produce a new true equation from an old true equation. The new true equation was all I cared about.

65. anonymous

you're completely right though, that if you want to solve for some variable or something, but doing equality preserving arithmetic on them, then you don't want to multiply by zero. But in this case, notice that I didn't need to preserve everything.

66. anonymous

Also, in most cases you wouldn't want to multiply by zero, because it destroys all information. BUT here, we said that there are two things with zero: it makes everything zero, and that 0 * 1/0 = 1. This second one isn't normally the case because we actually can't divide by zero. And so it's only in this "what if we could" scenario that we get some benefit out of multiplying both sides by zero. So I guess the reason that you feel strongly against multiplying by zero, is that in every other case, it's not a good thing to do. .... and the reason for that is because we can't divide by zero.

67. anonymous

for example, if you have a x = b, and you want to find x. You would multiply by 1/a, to get x. You could also multiply by any other number, except zero, and still have hope of finding x. If you multiplied by 0, then you have destroyed all information (unless I could make the zeroes disappear by divide through by them...)

68. anonymous

(.... like I assumed you could. and then ended up with 1=0)

69. skullpatrol

Hi @helder_edwin

70. helder_edwin

Hi

71. helder_edwin

I don't believe there's much more to say.

72. helder_edwin

I read everything u people wrote.

73. skullpatrol

I believe the argument: If a/0=c, then a=0*c. Is flawed. @helder_edwin

74. helder_edwin

first of all $$1\neq0$$ because otherwise we would have $\large a=1\cdot a=0\cdot a=0$ for every real $$a$$. so all the real numbers would be zero and that makes no sense and would render calculus useless.

75. skullpatrol

Agreed.

76. helder_edwin

in order to define division we gotta have multiplicative inverses (i don't the word in english for "recíprocos") i.e. $\large \frac{a}{b}=a\cdot b^{-1}$

77. helder_edwin

provided b is not zero. that is, zero doesn't have multiplicative inverse.

78. helder_edwin

suppose 0 actually has a multiplicative inverse, $$0^{-1}$$. then $\large \frac{0}{0}=0\cdot0^{-1}=1$ but also $$0\cdot0^{-1}=0$$. so we should have 0=1.

79. helder_edwin

therefore, zero does NOT have multiplicative inverse, so one cannot define division by zero.

80. skullpatrol

Therein lies the problem. I'm saying you can not write any number divided by 0 first. Because multiplication defines division.

81. helder_edwin

regarding the argument (proposition) $\large \frac{a}{0}=c\qquad\Rightarrow\qquad a=c\cdot0$

82. skullpatrol

Yes, how can you algebraically go from a/0=c --?--> to a=0*c

83. anonymous

@skullpatrol it sounds like you're saying "I don't believe it's true that we can't divide by zero" so then the argument is "okay suppose we can divide by zero, then..." and then you're saying "but how can you do that? You can't divide by zero..."

84. helder_edwin

maybe you professor was trying to make the point like this: "suppose we could write for $$a\neq0$$ $\large \frac{a}{0}=c$ then we could infer from this that $\large a=c\cdot0=0$ which contradicts the assumption"

85. skullpatrol

How do you "infer"? I want to know the algebraic steps used, Sir.

86. helder_edwin

"now. even if we let $$a=0$$ then we would have $\large \frac{0}{0}=c\Rightarrow 0=c\cdot0$ and this last equation is satisfied by any number c. so we end up having $\large \frac{0}{0}=0=1=2=\pi=e^\pi=...$ which is absurd.

87. anonymous

@skullpatrol do you know how a proof by contradiction works?

88. skullpatrol

yes

89. skullpatrol

a=bc defines a/b=c.

90. helder_edwin

that's the whole point. if u r supposing somehing is true then, all other relevant rules apply. including common algebra.

91. skullpatrol

So we are supposing if a/0=c, then how do you prove a=0*c.

92. anonymous

You are also supposing that there exists a number 1/0 such that 1/0 * 0 = 1.

93. helder_edwin

u don't.

94. skullpatrol

"u don't." why not?

95. anonymous

a/0= a*1/0 = c, then a * 1/0 * 0 = c * 0. Then a * 1 = c * 0 = 0. ie a= 0.

96. helder_edwin

because it's algebraic manipulation: $\large a\cdot0^{-1}=\frac{a}{0}=c$ $\large a=a\cdot0^{-1}\cdot0=c\cdot0$ there u have a "proof".

97. skullpatrol

But you multiplied both sides by 0

98. skullpatrol

And then left :(

99. anonymous

if you know that x = y, is it true that x * 0 = y * 0?

100. anonymous

just finished a maths degree... you? I'm trying to tell you that it's okay to multiply both sides of an equation by zero. I've just taken all undergraduate courses on algebra that my university offers. I think I'm qualified to state that it's okay in this case :p.

101. anonymous

(the above is a reply to the question by @skullpatrol patrol "what grade are you in?") Thanks for the implication that I don't appear very intelligent, buddy. Maybe I'll stop trying to help you understand it, eh...

102. anonymous

the question seems to have been deleted just as I answered.

103. helder_edwin

sorry i left. i'm in a place with the worst internet service ever.

104. helder_edwin

we (myself and @scarydoor ) are multiplying by zero because we are using a proof by con

105. helder_edwin

106. skullpatrol

So it is OK to multiply both sides of an equation by 0 even though the final equation is satisfied by any real number.

107. helder_edwin

u never multiply an equation by zero, unless, as u pointed out, u want to loose the "information" the equation provides.

108. skullpatrol

Thank you for confirming that Sir.

109. helder_edwin

@skullpatrol ???

110. skullpatrol

So why are we allowed to do it here? If a/0=c, then a=0*c.

111. helder_edwin

it is a proof by contradiction!!

112. anonymous

you are always allowed to do it. Just usually it doesn't do you any good. We only do it here because here, we have 1/0 * 0 = 1, because we assumed we could do that, because it's a proof by contradiction. In any other situation we know that dividing by zero destroys all information, and therefore is useless to us (even though it's correct, and the equality is preserved), so we don't do it in any other place. (even though we can. but it never helps us elsewhere)

113. anonymous

The reason people tell you not to is not because it breaks arithmetic rules. The reason they tell you not to is because it won't help you do anything, where we haven't temporarily altered the rules of arithmetic.

114. anonymous

That's why I asked you, if y=x, then does 0*y = 0*x? answer that, and then you'll see that there's nothing wrong with the proof. The only problem you find is that, normally you would find no practical value in multiplying by zero. Besides that, it doesn't break any rules to do so.

115. skullpatrol

But this (1/0)*0=1 is already a contradiction of the multiplicative property of 0, that is 0 times any number is 0, not 1.

116. anonymous

but wasn't your theory that you can divide by zero? That's what you're assuming is true. If you can, then 1/0 * 0 = 1. That's basically the definition of what it means to be able to divide by zero. That's what we assume, and then derive that a = 0 for any number a.

117. anonymous

Yes, it's a contradiction to the axiom that 0 times any number is 0. So that's one problem. What we show is that another problem, ignoring that first one, is that if you take it to be true then a = 0 for any number a.

118. helder_edwin

again. that's the whole point. u started with something u SUPPOSED to be true, and infered something absurd. ergo, your initial assumption was wrong.

119. skullpatrol

If a/0=c, <----u started with something u SUPPOSED to be true then a=0*c. <----inferred something absurd. ergo, your initial assumption was wrong.a/0=c

120. helder_edwin

yes. u can't divide by zero.

121. anonymous

the whole of the assumption is: 0 is invertible, and so for any number a, a/0 is defined. ie a/0 = c for some number c. That's the assumption that is proven false.

122. skullpatrol

And it is proven to be false by using the false assumption that 0 is invertible and using 0 as a multipier in transforming the equation.

123. skullpatrol

If a/0=c, <----u started with something u SUPPOSED to be true 0*(a/0)=0*c 0*(1/0)*a=0*c 1*a=0*c then a=0*c.

124. anonymous

yep. read a book on abstract algebra maybe.

125. skullpatrol

How can you prove something is false using a false assumption?

126. anonymous

when I asked if you know how a proof by contradiction works, you said you do... You should go and read about it. I might not be in a high enough grade for you to take me seriously, afterall.

127. helder_edwin

the discussion was very interesting. i hope we were helpful.

128. skullpatrol

It just seems so obvious that 0 times any number is 0. And then to use 0*(1/0) = 1 feels completely wrong!!! In my opinion :(

129. skullpatrol

I guess the lesson to learn here is "1/0" is not any number.

130. anonymous
131. skullpatrol

Thank you for your patience and guidance.

132. anonymous

I'll just leave this here http://www.khanacademy.org/math/arithmetic/number-properties/v/why-dividing-by-zero-is-undefined

133. anonymous

for example if you have 2 apples and you are supposed to split it with 0 people, it is not possible because there is no one to split it with

134. skullpatrol

You could say the answer to that question is nobody gets the 2 apples.

135. anonymous

no i mean you are required to split it to 0 people, it is not possible since you cannot split it with 0 people 2/0 = undefined

136. skullpatrol

Here: 2/0 "=" undefined you are using the "=" for "is" What I'm saying is 2/0 means nobody gets the 2 apples.

137. anonymous

what im saying is that you cannot just say no one gets the 2 apples if you are required to divide among 0 people

138. skullpatrol

If there is nobody around and you are required to divide 2 among 0 people what happens to the apples?

139. anonymous

it becomes undefined since its not possible to do so

140. anonymous

undefined is basically we dont know what happens

141. skullpatrol

Have you fulfilled your own requirement: "if you are required to divide "

142. anonymous

your question was why can you not divide by zero? so the requirement was to divide n by 0 and i just made an example by using n=2 to show you that it is undefined when you do so

143. skullpatrol

144. anonymous

i showed you why you cannot split 2 apples among 0 people since there is no one to split it with

145. anonymous

so what happens to the 2 apples? we dont know so we call that undefined

146. skullpatrol

But you said "it is undefined ***when you do so*** " so that means it ***can be done***?

147. anonymous

the apples are divided we just dont know how they are divided so we use the term undefined to answer it

148. skullpatrol

The apples are divided by 0?

149. anonymous

yea when you divide the apples by 0 we will get undefined since we dont know how they are divided

150. skullpatrol

I asked why can you NEVER divide by 0

151. anonymous

like i said your question was why can you never divide by 0 so i used an example of n = 2 we'll just use n then if you have n number of items and you want to split them among 0 people then you cannot because there is no one to split n items with, and we do not know how n is divided so we get an answer called undefined

152. anonymous

no matter what n is if you have no one to split it with, we will never know how n is divided

153. skullpatrol

That is what I said: no one gets the n. That is the answer. It is not undefined because nobody gets the apples is a well defined sentence.

154. anonymous

i didnt say no one gets the n i said we do not know how n is divided

155. skullpatrol

We do know how n is divided: "It is not divided" because nobody is there.

156. anonymous

it looks like you are making assumptions here you are saying since we dont know how n is divided you are assuming that n does not get divided instead, just because no one is there doesnt mean it does not get divided it means we dont know how it is divided so we say it is undefined

157. skullpatrol

If no one is there we do know nothing will happen to the apples.

158. anonymous

again you are making assumptions how can you be so sure nothing will happen to the apples?

159. skullpatrol

How can you be so sure we don't know?

160. anonymous

because it is more reasonable to say that we do not know rather that making an assumption and saying nothing happens

161. anonymous

you made a conclusion by saying nothing happens whereas i say we dont know, which means we havent come to a conclusion yet, so we just give it the term undefined to say we do know what happens

162. anonymous

dont know* (typo)

163. skullpatrol

So your answer is "we don't know" why we can never divide by 0.

164. anonymous

no as i said before we do not know how it is divided so we say its undefined

165. anonymous

since if we ever do divide by 0 do not know what happens so you are better off just not dividing by zero

166. mayankdevnani

@skullpatrol http://www.math.utah.edu/~pa/math/0by0.html

167. anonymous

when u dived by zero so ans will be infinite.means undefind which has no meaning

168. mayankdevnani

You cannot divide by zero because there is no meaningful result to that operation. No element of any given set of numbers - real, imaginary or otherwise - would fulfil this equation. Infinity is not a defined number, it is merely a symbol meaning "exceeding all values". You cannot use it to perform calculations like these. ok @skullpatrol

169. skullpatrol

So each friend doesn't get any apple is the answer?

170. skullpatrol

3/6 = 1/2 each 2/6 = 1/3 each 1/6 = 1/6 each 0/6 = 0 apples each

171. skullpatrol

"If you have 3 apples, and six friends, you can divide each apple in half that way, each friend gets half an apple."

172. skullpatrol

Are you talking about amount of apple per friend?

173. skullpatrol

So you are counting the number of pieces each friend gets.

174. skullpatrol

6/3 =half each friend 6/2 =3rd each friend 6/1 =6th each friend

175. anonymous
176. anonymous

true...its undefined. Watch the khan academy tutorial on it. Pretty logical and interesting.

177. anonymous

i want say something, we can't divided by zero but if my problem want to divided by zero ?! we know the velocity equal to difference between density over difference between time? $\frac{ v2-v1 }{ t2-t11 }$ question is what is the Instantaneous velocity? i.e find the velocity when t2 =t1?

178. anonymous

answer is we can't put t2=t1 directly but we but it by limit at t2 tents to t1

179. anonymous

you can't divide by zero for the same reason that it make no sense to ask how many miles per gallon i get on my bicycle $$a\div b=c\iff bc=a$$ try solving $$a\div 0=b\iff 0\times c=a$$ for $$c$$ and non zero $$a$$ for example try solving $2\div 0=c\iff 0\times c=2$ for $$c$$ and you see that you cannot

180. anonymous

typo there, i means try solving $a\div 0=c\iff 0\times c=a$ for $$c$$

181. skullpatrol

hmm... shouldn't it be a=bc defines a/b=c?

182. skullpatrol

@satellite73

183. skullpatrol

That is a=bc ---> a/b=c not a/b=c---> a=bc which you are combining to give a/b=c<--->a=bc

184. anonymous

Chuck Norris can divide by zero.

185. skullpatrol

That^ is all this thread needed

186. anonymous

you right because we con divided by zero @satellite73 but if i have to divide by value tends to zero what shall i do?

187. anonymous

@StupidGenius , if you're saying you're dividing 1 / n, and taking the limit as n gets closer to zero, then that is a limit that doesn't converge to any real number. It's just a case of a limit that doesn't converge to any real number. There are lots of them. That's all covered in the area of maths called real analysis.

188. anonymous

first line, should have said: "dividing 1 by n (i.e. 1/n)"

189. anonymous

yes i know some real analysis

190. anonymous

Just remember dividing by zero is done at your own risk, I choose to avoid doing such a thing.

192. anonymous

real analysis study the series and sequence at infinite terms and it's study to seek if the valve gives infinite or number (divergence and convergence )