x^sqrt(x) when x is 0 vs. x is approaching 0

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  • Опубліковано 7 лис 2024
  • Zero to the zero power, another example with the function x^sqrt(x). Be sure we know the difference between 0^0 when we do regular computation vs. 0^0 when we calculate limit. Enjoy!
    0^0 indeterminate form that doesn't give you 1, • a 0^0 limit that appro...
    x^x as x goes to 0+, • Limit of x^x as x goes...
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КОМЕНТАРІ • 304

  • @jzanimates2352
    @jzanimates2352 5 років тому +252

    Black penned pen, I got moved up to the top class in maths, all thanks to your videos! You are an awesome UA-camr!

    • @blackpenredpen
      @blackpenredpen  5 років тому +54

      That's so awesome!! Thanks for letting me know!! Great job to you as well!!!

    • @bruhmomenthdr7575
      @bruhmomenthdr7575 Рік тому

      ​@sunnygames4003Black penned pen 🧐🥸

  • @rosebuster
    @rosebuster 5 років тому +71

    I think that to be perfectly formal when using method 1, we'd first have to prove that the limit exists in the first place before we can call it L. Otherwise we're doing calculations using a value that's not a real number. In this case it didn't really matter, but I think things could go wrong in other situations.

  • @kaiandchanellesimmons502
    @kaiandchanellesimmons502 5 років тому +78

    Well done for 200000 subs. I just realised. I'm a uk sub currently doing maths at what we call A-Levels. You have helped me so much and want to say a huge thank you.

    • @blackpenredpen
      @blackpenredpen  5 років тому +17

      Kai and Chanelle Simmons you're very welcome, thank you for your nice comment!!

  • @itsiwhatitsi
    @itsiwhatitsi 4 роки тому +28

    You and 3Brown1Blue are the best UA-camrs for Math. You teach things better than in school. Very good job, greetings from Italy.Peace

  • @nootics
    @nootics 5 років тому +34

    Love your videos, I'm just at a "high school" and watch them for fun. My mathematical understanding got so much better as well, even though I haven't had most of what you do in your videos in class

  • @SartajKhan-jg3nz
    @SartajKhan-jg3nz 5 років тому +63

    'In your exam do not write "DO MORE WORK", do the work and give the answer' 😂😂

    • @inyobill
      @inyobill 4 роки тому +1

      Brings to mind that classic cartoon: "... and then a miracle happens ...".

  • @angelmendez-rivera351
    @angelmendez-rivera351 3 роки тому +19

    Well, y'all know already what I have to say about the "0^0 is undefined" claims. The mathematics pretty unambiguously show, under any reasonable definition of exponentiation, that 0^0 = 1 follows directly from that definition.
    THAT BEING SAID, I 100% agree with BPRP in that you should avoid confusing 0^0 (where 0 here is exactly the natural number 0, or the real number 0, whatever you prefer) with (0+)^(0+) (where 0+ is actually just really bad notation here for lim δ (δ -> 0+)). The former is an arithmetic expression, with 0^0 = 1, while the latter is a limit expression, and constitutes an indeterminate form. This means that lim f(t)^g(t) (t -> c), given the restriction lim f(t) (t -> c) = lim g(t) (t -> c) = 0, can be equal to 0, or any positive real number, or even perhaps +♾, depending on the exact relationship between f and g. Notice that this limit is not the same thing as 0^0, which again, is simply an arithmetic expression, where, as BPRP says, "the 0s are exact 0s, not limits."

    • @derwolf7810
      @derwolf7810 3 роки тому +3

      Offtopic here, but as i had issues in correcting my post (had to recreate that post).
      I wanted to thank you for pointing out that error (and let you know).

  • @gaurangagrawal6251
    @gaurangagrawal6251 5 років тому +79

    Me : No the answer can't be zero it must be 1.
    Bprp: calm down dude we have found lnx to be zero .

  • @Inspirator_AG112
    @Inspirator_AG112 2 роки тому +6

    0⁰ = 1 doesn't only work as a limit, but as an actual value.

    • @superhil4487
      @superhil4487 Рік тому +3

      nah, 0^0 = 1 is by a definition, it's similar with 0!=1

  • @Kumar-oe9jm
    @Kumar-oe9jm 5 років тому +18

    At 8:46, are u sure that u can multiply both the top and botton by 2x^(3/2) when the limit is x approaching 0+, bec it is like saying 2/3 multiply by 0 on the top and bottom and saying it equals 0

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому +23

      Kumar No, because it is a limit, so you are never actually multiplying by 0

    • @Vibranium375
      @Vibranium375 3 роки тому +1

      You haven't invoked the limit yet

  • @yee3816547290
    @yee3816547290 4 роки тому +11

    Function value is different from limit.
    The two need not to be equal.
    0^0=1 is the only reasonable definition.

  • @Sgrunterundt
    @Sgrunterundt 3 роки тому +1

    Here's a challenge with a satisfying solution that I just figured out myself:
    The function f(x)=x^x^a has one global extremum for a != 0 (a minimum when a>0 and a maximum when a

  • @mybarca8083
    @mybarca8083 11 місяців тому

    You can also make an educated guess as if x 0.25 and x^y being 0.5 in this case, if you fill in a smaller number like x=1/25 and fill in 1/5 for y then this will give you 0.53 thereby it can be assumed that when x approaches 0 and y approaches 0 as well, x^y will give you 1

  • @Zelda1990s
    @Zelda1990s 4 роки тому +6

    While it is true that 0^0 is an indeterminate form, I thought out of "convention", we say 0^0 is 1.

    • @angelmendez-rivera351
      @angelmendez-rivera351 3 роки тому +6

      Calling "0^0" an "indeterminate form" is to fail to understand what an indeterminate form actually is. Here is the simplest version of the argument: lim x^y (x -> 0, y -> 0) does not exist. Therefore, the value of lim f(t)^g(t) (t -> c) cannot be determined from the fact that lim f(t) (t -> c) = lim g(t) (t -> c) = 0 alone: you also need to have information relating f and g specifically. This inability to determine lim f(t)^g(t) (t -> c) from lim f(t) (t -> c) = lim g(t) (t -> c) = 0 alone means that this limit, with these restrictions on f and g, constitute an indeterminate form.
      Note: this is NOT the same as 0^0. 0^0 is not a limit. 0^0 is a numerical expression, and the value of this numerical expression is 1, which can be proven from the definition of x^y directly. Limits and forms have absolutely nothing to do with it.

  • @sabinrawr
    @sabinrawr 5 років тому +37

    Why can't we have a complex exponent? Why doesn't it make sense to have a negative base to a function power? As for solving problems involving the real world, you are right of course. But couldn't it still be done mathematically? Couldn't it at least be a little bit interesting to see what would happen?

    • @mike4ty4
      @mike4ty4 5 років тому +21

      You can, indeed, have a complex exponent, and raise negative bases to real powers. The most common example is the imaginary exponential e^(ix), which is frequently used as a description of waves. The trick is that if one uses negative/complex bases that the exponentials in general become ambiguous thanks to the ambiguity of the complex logarithm, and thus one has to specify what "branch" of the logarithm one is using for a given problem. Because of this, it is customary to stick in most cases to the typically more well-defined e^x (or e^z, for complex) with suitably-structured exponent.

    • @tipoima
      @tipoima 5 років тому +4

      After plugging -0.000001 in Wolfram Alpha, it seems like it converges on -1 (the answer was something like -0.9....+0.00001i)

    • @Rudxain
      @Rudxain 2 роки тому +1

      @@tipoima That's strange, when I put the actual limit approaching from the negative side, I got the same answer as from the positive side, +1 not -1

    • @JindraAG
      @JindraAG 2 роки тому +1

      I think an honest answer is you can, but at that point we've moved past simple calculus.

  • @nishadpatkar6636
    @nishadpatkar6636 Рік тому +1

    At 6:20, wouldn't it be easier to raise both sides to e so u get e^sqrt(x)+x and since x approaches 0+, you get e^0 + 0 which is 1?

  • @JeanSarfati
    @JeanSarfati Рік тому

    Thanks. I begin to get the symmetry between ln and e ! It's basic but well, now i visualize the two symmetric curves... Visualization in on a snap, developing algebra is like the speech, step by step then rigorous.

  • @sunsetflory
    @sunsetflory 5 років тому +3

    i thought about the 2nd way to solve it! we usually work in class with that form

  • @madanmohan877
    @madanmohan877 4 роки тому

    Please clarify: If y = g (x)/h(x) then
    y= g'(x)/h'(x) . Is it correct. That is to say: differentiating numerator and denominator simultaneously does not spoil the equation like multiplying the numerator and denominator with the same number. Please clarify it.

  • @Cloud88Skywalker
    @Cloud88Skywalker 5 років тому +2

    My intuition would have been to let both parts of the indeterminate form compete and see which one wins:
    0^x = 0
    x^0 = 1
    √x will get to 0 much faster than just x, so f(x) inclines to look like x^0 rather than 0^x, so the answer is 1.

    • @Cobalt_Spirit
      @Cobalt_Spirit 2 роки тому +1

      You say that as if the indeminate form 0^0 could only end up as either 0 or 1. Not true.

    • @Arthur-so2cd
      @Arthur-so2cd Рік тому

      @@Cobalt_Spirit root x is getting smaller much faster than x, therefore you have a small number to an even smaller number

  • @johnbohnenstiel605
    @johnbohnenstiel605 5 років тому +3

    could you please do the sum of the reciprocals of Mersenne numbers (3,7,15,31,63,...). It converges to about .606. Is the closed form 1/(sqr root of e)? Something else? Please show me! Thanks- love your content!

    • @nanamacapagal8342
      @nanamacapagal8342 Рік тому

      Wolfram showed up with something about (log(2) - q-digamma(1/2, 0, 2))/log(2)
      anything but a simple 1/sqrt(e)

  • @dwaraganathanrengasamy6169
    @dwaraganathanrengasamy6169 5 років тому +6

    Well,... Its time for shortcut. We very well know lim y->0 y^y = 1.
    The question is, limx->0 x^√x =
    Limx->0 ((√x)^√x)² = 1² = 1...!
    Tricks in limits(use of previous knowledge) is a lot enjoyable. I love limits😋💖💖💖

  • @Rudxain
    @Rudxain 2 роки тому

    I we want to get fancy, we could allow Dual and Complex numbers. The 2nd solution to sqrt(0) is called the "epsilon unit", so directly plugin it we get 0^e (the "e" in this context is not Euler, it's epsilon). For the limit from the negative side, we get the same answer as the positive side on WolframAlpha

  • @MrDazzlerdarren
    @MrDazzlerdarren Рік тому +1

    Is 0+ kinda like 0 + dx? If not how does it differ?

  • @JayTemple
    @JayTemple 2 роки тому +1

    I used the exponential form, but I replaced x with 1/u and let u go to infinity. I also didn't have to invoke "ln L equals," but I'm not sure that the former enabled the latter.

  • @gilber78
    @gilber78 5 років тому +4

    BPRP: I have a suggestion for “so you think you can take the derivative”
    Can you do d/dx of log base x of a (where the input of the log is a constant and the base of the log is a variable)? I know the answer- I’m curious how you’d do it in a video

    • @NoNameAtAll2
      @NoNameAtAll2 5 років тому +5

      log(a,b)=ln(b)/ln(a)
      problem?

    • @archithtelukunta4599
      @archithtelukunta4599 5 років тому +3

      Log base x of a can be written as loga/logx(its an identity).Therefore the derivative is same as the [derivative of 1/logx]*loga

    • @gilber78
      @gilber78 5 років тому +3

      @@NoNameAtAll2 I know but I just wanted bprp to do it because I know the answer already. I know the identity

  • @Christian_Martel
    @Christian_Martel Рік тому

    Could you calculate the same limit, but from the left hand side, lim f(x) where x -> 0- ?
    I would “imagine” this is possible.

  • @davidseed2939
    @davidseed2939 2 роки тому

    Note the google calculator gives 0^0=1
    so is there a function which is of the form 0^0 at x=0 but is not=1 as x->0+

  • @yee3816547290
    @yee3816547290 4 роки тому +2

    0^0 is different from limit of 0^0 form.
    Don't be confused.

  • @maxwellmogadam399
    @maxwellmogadam399 3 роки тому

    ive always thought about sqrt(0) this is a great video thanks!

  • @tarekhajjshehadi4670
    @tarekhajjshehadi4670 5 років тому +20

    What is (i!) ?

    • @jjeherrera
      @jjeherrera 5 років тому +1

      Do you mean (i)! ? If you do, my guess is it would be an alternative notation for the gamma function of 1+i, in which the expression for an integer is used for a complex number. (Gamma(n+1)=n!). Just a guess...

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому +1

      jjeherrera Black Pen Red Pen already addressed this

  • @atmonatmon2947
    @atmonatmon2947 5 років тому

    Shoot a video about what is t: a ^ b = b ^ a * t

  • @mhm6421
    @mhm6421 Рік тому

    In WolframAlpha when you enter Limit[x^sqrt(x),x->0] it gives 1? Why is that? How does 0 negative also go to 1?

  • @OculusOfficial
    @OculusOfficial 4 роки тому

    Depending on which pattern you want to infer its meaning from, 0 to the 0 will be whatever you want, I prefer to think that multiplying 0 by 0, 0 times we will get the result 0.
    The reason we say undefined I think is to satisfy the people who want to leap from a pattern to a solution without proof by not saying that they are wrong but by saying that we dont know.

    • @angelmendez-rivera351
      @angelmendez-rivera351 3 роки тому +1

      This is just wrong. 0^0 is not undefined, and most mathematicians acknowledge that 0^0 = 1 when they write their proofs, and even some textbooks acknowledge it as well. There are only a handful of mathematicians who refuse to accept the fact that 0^0 = 1, but this is just a petty denial of reality, no different than when high school students deny the fact that 0.(9) = 1 even after seeing rigorous proofs. As for BPRP or other teachers saying 0^0 is undefined, I have no idea why they do so. I have had conversations about this with BPRP in the past, and the arguments almost always boil down to the fact that lim x^y (x -> 0, y -> 0) does not exist, which is not actually a valid argument, because the definition of a function at a point is not contingent on the limit of the function to that point. If you simply substitute x = 0, y = 0 into the definition of x^y, you get a simple, unambiguous answer, and the fact that arguments from limits are being used to pretend that this is not the case baffles me and irritates me. Honestly, you may be right about one thing: it does feel as though the only reason teachers say 0^0 is undefined is solely for the purpose of making the minority of mathematicians who agree with them happy. However, I am not so dishonest as to claim to be certain that this is the reason behind everything, or that there is a reason at all, and I could just be misunderstanding what is happening. Regardless, I think this type of nonsense, where teachers teach things that are directly in contradiction with what mathematicians study and know is unacceptable under any circumstances. It is one thing to oversimplify a topic and introduce it infornally to students rather than rigorously so that they can get an intuition for the topic, it is a different thing entirely to outright lie to students.

  • @adamp9553
    @adamp9553 4 роки тому +2

    I could answer this question pretty immediately, without any calculus, understanding both (0+)^(0+) and how square roots work with real numbers. (0+)^(0+) is already 1; and a square root brings a term closer to 1; despite the power becoming closer to 1, lim with an infinitesimal will still approach x/x, which makes 1 for any non-abstract number.

  • @orisphera
    @orisphera 3 роки тому

    Fun fact: 1 is also the most logical way to define 0**0. That's what we get when we approach it in a straight line other than the line of constant base and that's also what it is in combinatorics. The original definition gives that because the product of 0 numbers is 1 and in my version of matrix theory (I'm pretty sure someone else came up with the same one) that's what the determinant of a 0x0 matrix 0I (which is the only 0x0 matrix) is

    • @MuffinsAPlenty
      @MuffinsAPlenty 2 роки тому +1

      Yes, the determinant of the 0x0 matrix is, indeed, 1. And this is _completely_ consistent with all of the theory of linear algebra and abstract algebra.

  • @नवलशर्मा-ड7ज
    @नवलशर्मा-ड7ज 2 роки тому

    Black pen red pen please make a video on x^1/lnx as x~0.👍

  • @Lasersharp
    @Lasersharp 5 років тому +2

    Is it true that 0^0 is undefined? I thought that was the case for a while, but some people say it's actually defined to be 1 (with valid arguments from a combinatorics perspective, as 0^0 is similar to 0!).

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому

      Lasersharp For the purposes of undergraduate mathematics, 0^0 is undefined just as the logarithm of a negative number is undefined for students in algebra 1.

    • @angelmendez-rivera351
      @angelmendez-rivera351 3 роки тому +1

      Okay, I am revisiting this 2 years later, and I have no idea why I said the nonsense that I said. 0^0 is unequivocally not undefined. 0^0 = 1 even for the purposes of algebra 1. It follows directly from the definition of exponentiation.

  • @hugo3222
    @hugo3222 3 роки тому

    If you did x^x before, just do x^sqrt(x)=(sqrt(x)^sqrt(x))^2=(y^y)^2 (with y=sqrt(x)), and you're done.

  • @vcvishalchandra
    @vcvishalchandra 5 років тому

    Thank you

  • @juanjuan-mi4gi
    @juanjuan-mi4gi 3 роки тому

    Como límite está bien....pero no tal símbolo cero a la cero es igual a uno...pues ello es solo un artilugio para justificar el cómputo tecnológico

  • @FairCheck
    @FairCheck 5 років тому +1

    Hi, I'm your big fan and I have one question that you could make a video... It's lim(x→0) (x^(1/x)) and lim(x→0) (x^(x / x))... Are these results same and is it possible to be solved. Thanks in advance

    • @nightish_one6007
      @nightish_one6007 5 років тому

      Lim(x-->0) (x^(x/x)) should be easy, since you can just divide the x's and be left with lim(x-->0) (x^1),which is just x.
      Lim(x-->0) x^(1/x) can be solved very similary by using the second method bprp used ( writing it as lim(x--0) e^(ln(x^(1/x))) and then saying it is equal to e^(lim(x-->0) (ln(x^(1/x))), then calculating that limit), and I highly encourage you to try solving it yourself!

  • @jacobpinson2834
    @jacobpinson2834 3 роки тому

    when the blue pen comes out, you know real maths is going down

  • @terapode
    @terapode 5 років тому

    And as always, a great video.

  • @tanushreebiswas9394
    @tanushreebiswas9394 4 роки тому

    Thanks sir..very nicely explained ❤️🤗

  • @otakurocklee
    @otakurocklee 4 роки тому

    Hmmm... the first method doesn't work because ln x is not continuous at x=0. So you can only bring the limit inside if you know that lim x->0 x^(sqrt(x)) is non-zero. We don't know that it is beforehand. Second method works before e^x is continuous everywhere.

  • @AngadSingh-bv7vn
    @AngadSingh-bv7vn 3 роки тому

    We can do the same thing for x^x and we'll get the same thing so lim as x->0+ of x^x is also one.

  • @lakshmivalavan2389
    @lakshmivalavan2389 Рік тому

    i think it is not if it is wrong please don't bother my answer
    answer:
    if you take any number like 3^3=27
    3^2=9
    3^1=3
    3^0=1
    why?;
    take;3^0
    we are doing multiplecation zero times is 1
    i mean we are not multipleing it
    [ 1*3^0 = 1]
    as the muliplecative identity dosen't change the value the 3^0 is just nothing and i don't mean about 0 i mean we are not doing it like;
    1*3^0=1(no operation have made here)=1
    now if we replace 3 as 0 the same works
    and the most told idea about 0^0 =0^1 * 0^-1
    where it is told to not take resibrocal of 0
    1 0^0
    -- = -------=0^-1 where it dosen't make any sence that we can't abel to assign two value to it thats why we can't take 0^-1
    0 0^1
    ad limits approches the value and non of the calculas can give a accurate value

  • @aee220phmunirabad
    @aee220phmunirabad 5 років тому

    Nice explanation.
    It is true that both X^x and X^sqrt(x) functions are equal to 1 when lim x->0; (i.e.x->0+)
    Please clarify!

  • @ayutac4056
    @ayutac4056 2 роки тому

    The nice thing is you can generalize this proof to show that x^f(x) -> 1 for x -> 0 for any superlogarithm function f :D
    EDIT: Ah wait no, f should be of the form x^a. f(x) = ln²(x) converges to 0 instead for example

  • @pedrosso0
    @pedrosso0 3 роки тому

    I am proud of myself, I did everything here except setting the limit as L and just putting it as e^(limit)

    • @pedrosso0
      @pedrosso0 3 роки тому

      Trying to do the limit as x goes to 0 minus. It's hard because of the imaginary part but I think the answer is that it goes to 1

  • @igxniisan6996
    @igxniisan6996 3 роки тому +1

    I love you no humu

  • @gabriellasso8808
    @gabriellasso8808 3 роки тому +2

    Lets define a^b:
    a^0 = 1
    a^1 = a
    a^(m+n) = a^m a^n (Done for rational numbers)
    For a real number x, you can prove that for any Cauchy series x_n, a^x_n converges and define a^x to be the limit of that.
    So, by definition, 0^0=1.
    Why people still say it is undefined?

    • @angelmendez-rivera351
      @angelmendez-rivera351 3 роки тому +1

      *Why people say still say it is undefined*
      That is a REALLY REALLY good question that nobody has been able to answer correctly.

  • @markgraham2312
    @markgraham2312 4 роки тому

    Try considering f(x) = |x|^x or f(x) = |x|^sqrt(|x|), then you can take lim x-?0- .

  • @pon1
    @pon1 Рік тому

    If it's infinitely approaching 0 can't it be said to be exactly 0 then? Just as infinitely approaching 1 like a third times three is exactly 1 even if it is 0.999999... (infinitely approaching 1)? So that 0^0 is 1 just as any other number ^0.

  • @bonzaiii3
    @bonzaiii3 5 років тому

    Great video!

  • @neoss988
    @neoss988 5 років тому +2

    0^0 is undefined?
    ok Let's define it : I put 0^0 = 1 X)

  • @victorsarmiento2552
    @victorsarmiento2552 5 років тому

    this is beautiful

  • @Mathelite-ii4hd
    @Mathelite-ii4hd 5 років тому

    what happened at 8:38?you said it will be -1/2x^-3/2 but then you wrote it down -1/2x^3/2

  • @frankharr9466
    @frankharr9466 5 років тому +1

    Yay!
    You know, when I was taking these classes and they told me to go and do work when I could intuit the answer, I didn't realize that they were trying to teach me techniques.
    Can you do approaching 0 from the i? Nah, that would be silly.

  • @tonyotag
    @tonyotag 5 років тому +1

    if the limit was coming from the left hand side would it not be a version of sqrt(-1)? or a version of imaginary numbers?
    so limit x^sqrt(x from 0- side) then is imaginary number answer?

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому +1

      tonyotag Not quite. The exponent will be imaginary, but the overall power is complex-valued. You can evaluate it using polar coordinates more easily.

    • @tonyotag
      @tonyotag 5 років тому

      @@angelmendez-rivera351
      I would "imagine" so.
      My comment was based more on blackpenredpen's comment in video about sqrt(x) is negative and therefore cannot exist, it does exist per immignary number i = sqrt(-1) in the exponent

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому

      tonyotag The limit was presented as a problem of real-valued functions, so imaginary numbers are not allowed.

  • @studentkaschool6902
    @studentkaschool6902 4 роки тому

    Nice

  • @shaidasabr5272
    @shaidasabr5272 4 роки тому

    Limit x apprach to zero for the square root of x is it exist?!
    i mean in general from both the left and right side if so can you explain

    • @anshumanagrawal346
      @anshumanagrawal346 3 роки тому

      No he said limit as x approaches 0 plus which means only the right hand side limit

  • @DanBurgaud
    @DanBurgaud 2 роки тому

    How I wished YT was available 40 years ago... LOL!

  • @PlayGuy200
    @PlayGuy200 5 років тому

    Why did you have to differentiate when it was: lim x->0+ (ln x / (1/sqrt x)) ?

  • @rafciopranks3570
    @rafciopranks3570 5 років тому +13

    I have an equations
    X^X+X=1

    • @ssissi12
      @ssissi12 5 років тому +9

      hum 0 ?

    • @rafciopranks3570
      @rafciopranks3570 5 років тому +1

      Yes but... there is one more answer :)

    • @Fahrradnerd
      @Fahrradnerd 5 років тому +4

      0? 0^0 is undefined so I would argue 0 is no solution

    • @ssissi12
      @ssissi12 5 років тому

      @@rafciopranks3570 yeah but i think it's an irrational number x=0.3036591268776...

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому +2

      Marcel No, 0^0 is generally taken by mathematicians to be 1.

  • @libelldrian173
    @libelldrian173 3 роки тому

    I can't stop smiling. ❤

  • @derarken73
    @derarken73 2 роки тому

    Maybe im dumb but:
    Can't you look at the power first, say that sqrt(0+) approaches 0 and therefore every number to the 0 power is equal to 1?

  • @bounpakhongphoomithep1640
    @bounpakhongphoomithep1640 5 років тому

    2³ = 1x2x2x2
    2² = 1x2x2
    2¹ = 1x2
    2º = 1 = 0º

  • @GOLDman4856
    @GOLDman4856 4 роки тому +18

    0^0 is actually equal to one as a computational question. One way to prove this is using blackpenredpen's "BEST FRIEND" formula

  • @mike4ty4
    @mike4ty4 5 років тому +5

    One of the things I'd want to point out is there's actually nothing weird or mysterious about "indeterminate forms". Rather, they are simply singularities of the arithmetical functions. For example, 0/0 is a singularity of the two-variable function ("binary function", which is why that / is called a "binary operation") f(x, y) = x/y at (0, 0), and it is a non-removable singularity, so there is no way to extend it continuously to that point. In other words, the two-dimensional limit does not exist. A one-dimensional limit giving the 0/0 form represents a certain path of approach to that singularity, and thus its value depends on the specific path taken, meaning you have to treat that limit individually, not generally. The same goes for 0^0, though there seem to be a bit of consensus that it should be defined to be 1. Nonetheless, that doesn't change its status as an indeterminate form since f(x, y) = x^y is still _not continuous at (0, 0)_ , and thus you are proscribed the use of direct substitution, just as for any more "obvious" discontinuous function that hasn't been graced with this mysterious "indeterminate" label. Unfortunately there are a lot of very helpful notions like this that get glossed over in much maths teaching dogma as embodied in the textbooks, and I think it's worse off for it. Rather one is just told that certain forms can't be used, without much inkling as to _why_ or what the notion of "indeterminate form" even _means_ , and, moreover, this shows there are many other forms than just the ones listed: _any_ non-removable singularity of a polydimensional function (or n-ary, if you prefer) is an indeterminate form when a lower-dimensional limit of some composition of that function yields it.

    • @cycklist
      @cycklist 5 років тому +4

      LOL some people just love to show off, don't they.

    • @mike4ty4
      @mike4ty4 5 років тому +2

      @@cycklist I thought this was a mathematics site, where we discuss about maths and thus that a detailed post about a piece of maths related to the specific subject matter of the video would be welcomed.
      The point was to try and provide information some might find useful, given that this is another one of those things (kind of like the fact that an indefinite integral with disconnected domain, like the integration of 1/x to "ln |x| + C", actually effectively has more than one constant of integration) that isn't necessarily mentioned even though it should be and would remove some apparent arbitrariness in the exposition of the material. By posting this, it may help some to understand things they didn't before due to possible shortcomings of the usual presentations. Not to "show off".
      Don't just assume you know what motivates people, especially those you don't know very well. You could be wrong. And while this is a rather trivial matter in the grand scheme of things, this same _thinking_ and approach to people can cause real hurt in the world in other circumstances. It can be the origin of prejudices (like racism), of other-wallet worrying, and ultimately perhaps, even of wars. Keep that in mind, and learn to be more Good, since that's what the real purpose of human life is, at least I believe, from a metaphysical point of view.

    • @MuffinsAPlenty
      @MuffinsAPlenty 4 роки тому +2

      mike4ty4 - This is probably the best comment I've seen on this video. It's a shame that so many people are willing to throw their understanding of limits in the trash when it comes to talking about defining 0^0.

    • @angelmendez-rivera351
      @angelmendez-rivera351 3 роки тому +1

      I am 2 years late, but this is a big agree from me. In fact, this comment was very illuminating to me, and one of a few speeches that sent me down on a quest to re-educate myself in mathematics and free myself from the problematic mathematics-education dogma that plagues people on a seemingly world-wide scale. This comment should be pinned.

  • @DadicekCz
    @DadicekCz 5 років тому

    Or you could just instead of these long (but interesting!) calculations say this (For example with number 2) :
    2^4 =16
    2^3 = 8
    2^2 = 4
    2^1 = 2
    So
    2^0 must equal to 1, because everytime you divide the equation by 2
    Works with all simple numbers

    • @erikosterling3311
      @erikosterling3311 5 років тому +1

      no, that's just a way to say that x^0 = 1. The problem arrives when we realise that 0^x is always equal to 0. So if you have 0^0, then that's in the form x^0 so it ought to equal 1, but it's also in the form 0^x so it ought to equal 0. That's what indeterminate form means: you can't tell just by looking at the numbers what the result should be.
      2*infinity is not indeterminate. x*infinity is always infinity and 2*x can be any number, including infinity. 2*infinity must therefore be infinity. No contradiction.
      2*5 is not indeterminate. 2*x can be any number and 5*x can be any number. so 2*5 = 10 does not imply any contradiction.
      0*infinity is indeterminate. 0*x = 0, |x*infinity| = infinity. So is |0*infinity| equal to 0 or infinity? Outside the limit world it's undefined, and in the limit world we need to look at the context.
      Lim x-->infinity of x * (1/x) will be equal to 1.
      Lim x-->infinity of x^2 * (1/x) will be equal to infinity.
      Lim x-->infinity of x * (1/x^2) goes to 0.
      Lim x-->infinity of (4+pi*i)x * (1/x) goes to 4+pi*i.
      They are all in the form 0*infinity but they all go to different values. That's what it means for a form to be indeterminate.
      If you want to you can try to find simple examples for each member in the indeterminate family (infinity - infinity, 0/0, 0^0, 1^infinity, infinity^0, infinity/infinity, 0*infinity) that shows they are indeterminate; two seperate limits in for example the form infinity - infinity that end up going to different values.

    • @seroujghazarian6343
      @seroujghazarian6343 4 роки тому

      @@erikosterling3311 you're taking LIMITS
      As far as non-limit numbers go, most of the above expressions are undefined, except 0⁰, which is 1

    • @erikosterling3311
      @erikosterling3311 4 роки тому

      ​@@seroujghazarian6343
      Let us assume 0⁰ = 1 and show that that leads to a contradiction.
      0⁰ = 1
      ln(0⁰) = ln(1)
      0*ln(0) = 0
      0*undefined = 0
      If we assume 0⁰ to be 1 we get that 0*undefined is equal to 0. Undefined * 0 is undefined and as such 1 is undefined. However, 1 is defined, so there is the contradiction.
      If you thoroughly beleive that ln(0) is -∞ (which I don't much care if you do) then we still have a problem since 0*∞ is also undefined.

    • @MuffinsAPlenty
      @MuffinsAPlenty 4 роки тому +1

      Erik Österling - Not a valid argument.
      Your argument also shows that (-1)² = 1 is wrong.
      Assume (-1)² = 1
      ln((-1)²) = ln(1)
      2*ln(-1) = 0
      But ln(-1) is not 0, so we have a contradiction: two nonzero numbers multiplying together to give 0.
      The logarithm rule that ln(b^c) = c*ln(b) only holds in certain circumstances. You cannot apply it haphazardly.

    • @angelmendez-rivera351
      @angelmendez-rivera351 3 роки тому +1

      @@erikosterling3311 *The problem arrives when we realize that 0^x is always equal to 0.*
      0^x is obviously NOT equal to 0 always. For example, if x = -1, 0^x is not 0. If x = i, 0^x is not 0. There is no reason why 0^x should be 0 if x = 0.
      *So if you have 0^0, then that's in the form x^0 so it ought to equal 1, but it's also in the form 0^x so it ought to equal 0.*
      This is an invalid argument, because while being of the form x^0 "should imply" equality to 1, I already explained above that 0^x is not always equal to 0, and there is no reason to assume a priori 0^x should be 0 for a given value of x.
      *That's what indeterminate form means: you can't tell just by looking at the numbers what the result should be.*
      No, this is definitely not what "indeterminate form" refers to. Indeterminate forms are, by definition, limit expressions, which under certain restrictions, cannot have their value deduced from those restrictions alone. 0^0 is an arithmetic expression, and so, it is not indeterminate.
      *x·infinity is always infinity*
      Ah, so we are just going to ignore the existence of x = 0. I see. Anyway, this is technically nonsense, since ♾ is not a number and you cannot do multiplication with it.
      *0·infinity is indeterminate.*
      No, 0·infinity is nonsense, because "infinity" is not a number. lim f(t)·g(t) (t -> c), with the restrictions that lim f(t) (t -> c) = lim 1/g(t) (t -> c) = 0, is indeterminate. This is not the same thing as the expression "0·infinity."
      *Let us assume 0^0 = 1 and show that it leads to a contradiction.*
      It does not lead to any contradictions whatsoever.
      *0^0 = 1; ln(0^0) = ln(1); 0·ln(0) = 0*
      ln(x^y) = y·ln(x) is not true in general. (-1)^2 = 1 implies ln[(-1)^2] = ln(1). If we assume that ln(x^y) = y·ln(x) is true in general, then ln[(-1)^2] = 2·ln(-1) = ln(1) = 0, so 2·ln(-1) = 0, which is clearly false. Does this mean (-1)^2 is undefined? No. (-1)^2 = (-1)·(-1) = 1 is a fact that can be proven from the field axioms. What led to the contradiction was claiming that ln[(-1)^2] = 2·ln(-1) is true, when in fact, it is false, and ln(x^y) = y·ln(x) is false in general. It only holds for rather special cases of x and y. So your proof is invalid, and it fails to demonstrate that 0^0 = 1 leads to a contradiction. This is consistent with my claim above: there are no contradictions that you can prove with this "assumption," which is in reality a direct consequence of the definition of exponentiation.
      When n and m are natural numbers, n^m denotes the product of the elements of the m-tuple where all its elements are equal to n. Therefore, 0^0, by definition, denotes the product of the elements of the 0-tuple where all its elements are 0. Since the 0-tuple is the empty set, the product of its elements is vacuously 1, because the empty set has no elements. Therefore, 0^0 = 1. Actually, the secret in the identity x^0 = 1 is the fact that the 0-tuple contains no elements, so it does not matter if the base is 0 or not: the base is never contained in the 0-tuple, which means the 0-tuple is unique and base-independent. You can prove the 0-tuple is equal to the empty set, which is also unique, by the way. So the only way you can dispute 0^0 = 1 is if you dispute that the product of no elements of the empty set is 1. Good luck disputing that, and if you dispute that, you would be proving x^0 = 1 is false for all x, not just x = 0.

  • @shipsteer2891
    @shipsteer2891 2 роки тому

    I know that this is from a long time ago, but wouldn't the 1/sqrt(x) be x raised to the power of 1/2 instead of -1/2?

    • @asianhaydenxd
      @asianhaydenxd 2 роки тому

      No; the exponent is negative because it's in the denominator.

  • @adhirachannel1148
    @adhirachannel1148 5 років тому

    Can u plz help me how to integrate e^sinx

  • @comingshoon2717
    @comingshoon2717 4 роки тому

    Me impresiona

  • @a2333232332
    @a2333232332 5 років тому

    All most all f(x)^g(x) limit -> 1
    when both f,g -> 0

  • @nanamacapagal8342
    @nanamacapagal8342 3 роки тому

    3rd method: do it numerically. Compute 0.0000000000000001^0.00000000000000005
    4th method: graph it.

  • @orisphera
    @orisphera 3 роки тому

    I think the second problem can be reduced to lim(x->0)x**x

  • @_ssodaaa
    @_ssodaaa 5 років тому

    Can I use f(x) = x^x to consider ?????

    • @blackpenredpen
      @blackpenredpen  5 років тому

      Yes. I did that before already. That's why I did x^sqrt(x) in this vid.

    • @_ssodaaa
      @_ssodaaa 5 років тому

      @@blackpenredpen thanks. Very mush

  • @rpenguinboy
    @rpenguinboy 5 років тому +1

    BEAARDD!!! WOWWWW!!

  • @MrConverse
    @MrConverse 5 років тому

    What’s the minimum of the function?

  • @Peter_1986
    @Peter_1986 5 років тому

    I once spent like 30 minutes trying to solve a very weird example problem, and then the solution said that a solution didn't exist.

  • @seroujghazarian6343
    @seroujghazarian6343 4 роки тому +1

    0^0 is NOT Undefined!😡

  • @isobar5857
    @isobar5857 3 роки тому

    But why did you not just use the difference quotient, [[f[x] +[h]-f[x]]/h ? I'm lost !

  • @aws1379
    @aws1379 3 роки тому

    Both are the same!

  • @theophonchana5025
    @theophonchana5025 3 роки тому

    0^(0) = undefined

  • @thomvandenhil4717
    @thomvandenhil4717 5 років тому

    Why can't you just immediately enter 0⁺, so that you get: (0⁺)^√0⁺ = (0⁺)^0 = 1, since 0⁺ is like saying 0.0000001 and 0.0000001^0 = 1

  • @biscuit_6081
    @biscuit_6081 11 місяців тому

    Why does my calculator show 1 when I plug in 0^0?????????????

  • @JoshuaHillerup
    @JoshuaHillerup 5 років тому +1

    Is there a situation where you have (0+)^(0+) not equalling 1?

    • @angelmendez-rivera351
      @angelmendez-rivera351 3 роки тому +1

      Careful. 0^0 = 1, but 0+ is just bad notation for expressing lim ε (ε -> 0), so (0+)^(0+) is bad notation for expressing lim x^y (x > 0, y > 0, x -> 0, y -> 0). This limit does not exist, but if you consider x = f(t), y = g(t), such that lim f(t) (t -> c) = lim g(t) (t -> c) = 0, then lim f(t)^g(t) (t -> c) can be equal to any positive real number or to 0, depending on the specific relationship of given f and g.

    • @MichaelRothwell1
      @MichaelRothwell1 3 роки тому

      An example where the limit is 0 is f(x)=e^(-1/x²), g(x)=x, so f(x) & g(x) -> 0 from above as x->0+, and f(x)^g(x)=e^(-1/x)->0 as x->0+.

    • @MichaelRothwell1
      @MichaelRothwell1 3 роки тому

      An example where the limit is a (for 00+, and f(x)^g(x)=a->a as x->0+.

    • @MichaelRothwell1
      @MichaelRothwell1 3 роки тому

      The limit of f(x)^g(x) as x->0+ if f(x) & g(x) -> 0 from above must be ≤1.
      To see why, suppose f(x)^g(x)->a as x->0+. Then ln[f(x)^g(x)]->ln(a). Now ln[f(x)^g(x)]=g(x)ln[f(x)]. For x sufficiently close to zero, f(x)

  • @kepler4192
    @kepler4192 2 роки тому

    0^0=1, don't believe me? use the binomial theorem for (x+y)^n when y=0

  • @kamalrihani9609
    @kamalrihani9609 5 років тому

    by definition lim xlogx =0 when x reach 0

  • @MikehMike01
    @MikehMike01 3 роки тому

    According to Wikipedia 0^0 = 1

  • @vincentlaw4580
    @vincentlaw4580 5 років тому

    What is the limit for x>0-

    • @justabunga1
      @justabunga1 5 років тому

      The limit DNE because it’s not in the domain due to the square root and the base cannot be negative.

  • @dudurododoizi8547
    @dudurododoizi8547 5 років тому +11

    can we have a 0^0 situation where it's not equal to 1?

    • @eric3813
      @eric3813 5 років тому +5

      Yes

    • @zblxst9347
      @zblxst9347 5 років тому +16

      Yes we can : lim(x-->0) 0^x = 0

    • @IoT_
      @IoT_ 5 років тому +4

      @@zblxst9347 only right side limit or zero plus. You can't evaluate limit as x goes to zero minus of 0^x

    • @dudurododoizi8547
      @dudurododoizi8547 5 років тому

      @@kyro1197 oh thanks I didn't see till end

    • @zblxst9347
      @zblxst9347 5 років тому

      @@IoT_ Obviously we can't. I didn't think about it but it's a good precision

  • @procerpat9223
    @procerpat9223 3 роки тому

    Clever

  • @sabergad9265
    @sabergad9265 4 роки тому

    Good but lighting reflected on w borad

  • @BizVlogs
    @BizVlogs 3 роки тому

    Guys help me. Does the (limit of the) indeterminate form 0^0 ever equal something besides 1? Can anyone give me an example?
    (Don’t say 0^x because that’s not really indeterminate form)

    • @MuffinsAPlenty
      @MuffinsAPlenty 2 роки тому +1

      You can take things of the form (e^(-x^2))^(-c/x^2) where c is any real number. Then take the limit as x approaches infinity.
      The base, e^(-x^2), tends to 0. The exponent, c/x^2, also tends to 0. So we have the limiting form (→0)^(→0). However, using exponential rules, for all sufficiently large x, we have e^(-x^2*-c/x^2) = e^c. So the limit is e^c. (Again, c can be any real number, so the limit could be any positive number.)
      But there is a theorem that if your two functions (the base function and the exponent function) are sufficiently nice (they have power series expansions defined around 0), then you will always get 1 for the limit. So yeah, most of the examples people come up with for (→0)^(→0) will ultimately have a limit of 1, since they tend to stick to nice functions. But it is possible to get something else.

  • @rhc1560
    @rhc1560 Рік тому

    But in a video u said 0^0= 1 by convention

  • @YodaWhat
    @YodaWhat 5 років тому

    blackpenredpen
    -- I wish you would talk a little more slowly. You have bursts of high-speed speech in which I cannot understand a word you say... and I understand Isaac Arthur perfectly.

  • @HenrySchach
    @HenrySchach 4 роки тому

    In comparison, lim x-> 0+ x^x is 1