Derivative of Exponential Function (e^x) From First Principles

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  • Опубликовано: 1 фев 2025

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  • @AlongCameAirxD
    @AlongCameAirxD 3 года назад +216

    This is the only video I found that solved this problem and that limit without using the circular logic of L'Hopital's rule. You are the only one that showed that limit to truly be 1. Earned a like from me.

    • @lukewarm7465
      @lukewarm7465 2 года назад +2

      Same here

    • @agytjax
      @agytjax Год назад +1

      @@lukewarm7465
      He could have avoided the complicated route of proving using natural log (ln). Here is the proof :
      We have e^x.Lim(h->0){(e^h - 1)/h} --- (1)
      We know that e=Lim(h->0){(1+h)^(1/h)}
      Substituting the value of 'e' in (1) above, we get :
      => e^x.Lim(h->0){([1+h]^(h*1/h) - 1)/h}
      => e^x.Lim(h->0){([1+h]^(1) - 1)/h}
      => e^x.Lim(h->0){(1+h-1)/h}
      => e^x.Lim(h->0){(h)/h}
      => e^x.Lim(h->0){1}
      => e^x

    • @sphakamisozondi
      @sphakamisozondi 11 месяцев назад

      Sane here. This is a satisfying explaination to this problem

    • @boguslawszostak1784
      @boguslawszostak1784 9 месяцев назад

      You don't have this problem if you DEFINE ln(x) as the integral from 1 to x of 1/u du, and the function e^x as its inverse function.

    • @spudhead169
      @spudhead169 8 месяцев назад +3

      Unfortunately it's still kind of circular. d/dx e^x = e^x is itself a definition of e, in that e is the only value of n that satisfies d/dx n^x = n^x . You cannot prove a definition, if you could you wouldn't need it to be a definition. Trying to prove it will always result in a circular argument with a derivative because such a proof requires the use of the definition of e in some form, and since all definitions are equivalent, using the definition of e is equivalent to using the derivative definition and thus circular.

  • @emmanuelmasemola1014
    @emmanuelmasemola1014 2 года назад +43

    Very sincere, very clear, I wish we were together during my university days, these are the kind of channels that deserve subscription, you don't need to tell us to subscribe , we have fallen inlove with your content.

  • @nadineabusaleh9401
    @nadineabusaleh9401 11 месяцев назад +17

    The way he looks at maths as it is magic and charm gave we a really beautiful vibes , i have never seen a teacher that is calm and has this clarity before . I hope he continues .

    • @RobMcCreery
      @RobMcCreery Месяц назад

      I just came here to say the same thing! I have recently become a teacher late in my career, and I have this man's clarity and his joy in demonstrating maths. An inspiration!

  • @AcryllixGD
    @AcryllixGD 2 года назад +45

    Honestly one of the best videos ive ever watched! Im an a level student in the uk learning about calculus and this video made it so clear as to why this was the case! Really good video!

  • @herbertsusmann986
    @herbertsusmann986 4 месяца назад +1

    It has literally been 50 years now since I learned this stuff so many of the details I've forgotten (like how to derive things like this from first principles). This is an elegant way to do that for e^x!

  • @robread-jones3698
    @robread-jones3698 2 года назад +6

    We all know there is something inherently beautiful in mathematics, but that explanation with its cool, calm, clear and entertaining delivery really emphasized that point. It was a joy to watch.
    A video has to be something particularly special to get both a like and a subscribe out of a grumpy old git like me. Job done here. I'm looking forward to watching more of your videos.

  • @xebby9
    @xebby9 2 года назад +10

    The BEST explanation I've watched about this derivative

  • @MrDipanmehta
    @MrDipanmehta 2 года назад +6

    This is the most critical video - unlike so many other dealing with this topic. However, this doesn't comes on top of youtube search try adding some keywords or description mentioning "exponential function". This is amaziing video thank you.

    • @PrimeNewtons
      @PrimeNewtons  2 года назад +3

      Thank you for the suggestion, I have made some changes.

  • @sphakamisozondi
    @sphakamisozondi 11 месяцев назад +1

    I have never, not even in my maths books I used at university, have someone explained why, _lim_ _h -->0_ *{exp(h) - 1}/h =1*
    Well done sir. Much love from South Africa

  • @GicaKontraglobalismului
    @GicaKontraglobalismului Год назад +3

    Great! I have always calculated the derivative of the exponential using the derivative of its inverse, that is, of the logarithm, and always thought the direct calculation impossible.
    In Romanian Language "to learn" is said "a invata" which is formed of words "in" and "viata" which mean "in" and "life" ; in other words, the Romanian the word for "to learn" actually means "to be alive" which is exactly what you said in the end. Your mind already thinks Romanian! I also appreciate your style, the blackboard, the chalk, and last but not least your calligraphy!

    • @PrimeNewtons
      @PrimeNewtons  Год назад +2

      Wow! This is inspirational! Thank you for your comment.

  • @labibbidabibbadum
    @labibbidabibbadum Год назад +1

    Liked, subscribed, coming back. I’m helping my teenage son who is just starting with calculus. This kind of clarity in teaching is wonderful.

  • @Einstein.Albert.official
    @Einstein.Albert.official Год назад +9

    man you have a beautyful handwrigting

  • @goldCrystalhaze
    @goldCrystalhaze Год назад +2

    I saw an explanation of the derivative of a^x in a lecture, which I never actually understood and I was going to search for a better explanation these days. Your video came by chance and it is fantastic! Thank you so much! I have subscribed to your channel.

    • @No-cg9kj
      @No-cg9kj Год назад +1

      e and ln love to sneak their way into everything lol. If you haven't got to calc 2 yet be prepared to see them a lot haha.

  • @mihaipuiu6231
    @mihaipuiu6231 Год назад +1

    Sir,you are a good teacher.Why? Because your writing is very nice, you work on a clean table, but very important...your proof is very clear and you explain like MICHAEL PENN. Thanks, SIR.

  • @Katutowavicle
    @Katutowavicle 2 года назад +8

    I wanna thank not just for the great explanation but the positive energy you put in the video

  • @renesperb
    @renesperb Год назад +2

    A nice and clear presentation,and , in contrast to many other videos of this type , a good handwriting , making it easy to read.

  • @MrWildcathendrix
    @MrWildcathendrix Год назад

    I've just studied this demonstration in my Math 1 book for my first year of Computer Science Engineering university course, it's exactly the same as you write, but the way that you explain it makes math much more fun!

  • @kingbeauregard
    @kingbeauregard Год назад +1

    Oooh, I like your style! You're really clear, and your enthusiasm is infectious. Subscribed!

  • @obadamh7030
    @obadamh7030 2 года назад +1

    I finally found someone to clear it up simply, I really owe you

  • @debjanimukherjee502
    @debjanimukherjee502 Год назад

    Reminiscing my college days with you and enjoying my retired life ❤

  • @donald_w
    @donald_w 7 месяцев назад

    You are an incredible teacher! Thank you for explaining this so well and not overlooking the small details 😊

  • @agytjax
    @agytjax Год назад +4

    From 4:35 onwards, you could have avoided the complicated route of proving using natural log (ln). Here is the proof :
    We have e^x.Lim(h->0){(e^h - 1)/h} --- (1)
    We know that e=Lim(h->0){(1+h)^(1/h)}
    Substituting the value of 'e' in (1) above, we get :
    => e^x.Lim(h->0){([1+h]^(h*1/h) - 1)/h}
    => e^x.Lim(h->0){([1+h]^(1) - 1)/h}
    => e^x.Lim(h->0){(1+h-1)/h}
    => e^x.Lim(h->0){(h)/h}
    => e^x.Lim(h->0){1}
    => e^x
    Q.E.D

  • @SanePerson1
    @SanePerson1 Год назад

    A nice side result from this extremely nice demonstration is hidden in the penultimate line. I'm so accustomed to taking the derivative of e^x, that I forget what constant I should use when taking the derivative of a^x. But the entire derivation you've given doesn't change for that case, EXCEPT that in the middle panel, one should use the base-a log instead of the natural log (ln). so you get (d/dx)a^x = [1/log(e)]a^x, where the log is the base-a log. In particular, this recovers the conversion factor for base-10 log and natural log: 1/log(e) ≈ 2.303.

  • @hiderr6805
    @hiderr6805 Год назад +12

    You may want to substitute (e^h - 1) with (1/n) instead of n. This way you would get easily to the most commonly known definition of e, that is lim n->inf (1+1/n)^n instead of (1+n)^(1/n)

    • @PrimeNewtons
      @PrimeNewtons  Год назад +6

      Thank you. I will investigate that option

  • @user-dp9yn7zf4l
    @user-dp9yn7zf4l Год назад +1

    Amazing video, first time learn the derivative of e^x this well! I have a question, when we taking the reciprocal, do we need to show that the denominator is not zero (at about 7:45)?

  • @mohamedsaith4532
    @mohamedsaith4532 2 года назад +3

    Wow!!!!!!
    How amazing explanation 👏🏻👏🏻👏🏻👏🏻👏🏻

  • @aram5642
    @aram5642 Год назад +1

    Greatest blackboard and chalk I have seen of all math videos here. The lighting would benefit from some angle or diffusor though ;)

    • @PrimeNewtons
      @PrimeNewtons  Год назад

      Thank you. I am still trying to find the pest lighting conditions for videos. I hope the newer videos are better lit in your opinion.

  • @anonymous-ui7il
    @anonymous-ui7il 2 года назад +1

    I am binging on your videos, it has helped me a lot with calculus.

    • @PrimeNewtons
      @PrimeNewtons  2 года назад

      I'm glad you find them helpful. Thanks for the feedback.

  • @invisiblelemur
    @invisiblelemur Год назад

    Beautiful. Thank you for getting me as excited about this as you are!!

  • @kiturundee9077
    @kiturundee9077 3 года назад +3

    Beautiful video. Love the energy 😀

  • @felipecanogiraldo2499
    @felipecanogiraldo2499 4 месяца назад

    Very greatful of this explenation, great teacher, great video, great smile haha. Keep it on like that.
    Greetings from colombia !

  • @randalltucker9343
    @randalltucker9343 Год назад +1

    Very nicely done, sir! Great video!

  • @RobertKashila
    @RobertKashila 4 месяца назад

    The guy is a logarithmic genius 👌

  • @tafadzwachigumbu4276
    @tafadzwachigumbu4276 Год назад +1

    This is a very good presentation. Thank you sir.

  • @averagehooligan620
    @averagehooligan620 Год назад +1

    Mindblown. Been searching for this.

  • @okeuwechue9238
    @okeuwechue9238 10 месяцев назад

    Great explanation. Thnx.
    An alternative explanation would also be expressing the natural exponential function as a Taylor series expansion and then differentiating each individual term to show that the resultant expression is the same as the original series

    • @PrimeNewtons
      @PrimeNewtons  10 месяцев назад +1

      That would not be from first principle, though.

    • @okeuwechue9238
      @okeuwechue9238 10 месяцев назад

      True :-)@@PrimeNewtons

  • @hiderr6805
    @hiderr6805 Год назад +2

    What an amazing video! Thank you so much! So cool, the only source I found using only elementary methods...

  • @Ray1tx
    @Ray1tx 11 месяцев назад +2

    Wonderful explanation!

  • @theeligator8728
    @theeligator8728 10 месяцев назад

    thank you sooo much i love your positivity! keep going +1 follower gonna recommend to my peers.

  • @souverain1er
    @souverain1er Год назад

    Great explanation. Love it. Never learnt this in calculus

  • @binhql
    @binhql Год назад +2

    Great! You've just made by day :D Appreciate it a lot.

  • @kopisusu3781
    @kopisusu3781 3 года назад +5

    this really cleared things up for me. thankyou very much!

  • @petersamantharadisich6095
    @petersamantharadisich6095 2 года назад +2

    it might be easier to simply start with that definition of e and expand in a power series
    e^h = lim_n (1+h+h^2/2+...+h^n/n!)
    then subtract 1
    e^h - 1 = lim_n (h+h^2/2+...h^n/n!)
    then divide by h
    (e^h - 1)/h= lim_n (h+h^2/2+...h^n/n!)/h
    = lim_n (1+h+h^2/2+...h^(n-1)/n!)
    then take limit with respect to h (limit is 1 and doesn't depend on n), then with respect to n (still 1)

    • @PrimeNewtons
      @PrimeNewtons  2 года назад

      I agree. I wanted to stay within knowledge from precalculus and highlight that manipulation I showed.

    • @znhait
      @znhait Год назад +2

      This is circular reasoning. You just gave the Maclaurin series for e^x, which is obtained by finding the derivative of e^x. If someone is finding derivatives from first principle, the assumption is that no result that includes the derivative--other than the definition itself--can be used.

    • @petersamantharadisich6095
      @petersamantharadisich6095 Год назад

      @@znhait I don't think it is, as you can derive the power series by expanding the definition used in the video...
      e^x=lim_n(1+x/n)^n
      = lim_n{sum_j (x/n)^j × n!/[j!(n-j)!]}
      = lim_n{sum_j x^j/j! × [n/n][(n-1)/n]...[(n-j+1)/n]}
      = lim_n{sum_j x^j/j! × [1][1-1/n]...[1-(j-1)/n]}
      = lim_n {sum_j x^j/j!} × lim_n{[1][1-1/n]...[1-(j-1)/n]}
      = lim_n {sum_j x^j/j!}
      The above does not refer to derivatives of e^x, there is no need to use circular reasoning to get the result this way.

  • @GoodMorning-t7x
    @GoodMorning-t7x Месяц назад

    Thanks for the video. Can you at the end of videos also leave the frame for some seconds so it would be easier to take screenshots. Have a great day

  • @icafe36485
    @icafe36485 2 года назад +2

    Hi Master, I enjoy your teaching method💐🌹👏

  • @Rob1066-
    @Rob1066- Год назад +1

    Great pure math explanations!

  • @sakangbenjamin
    @sakangbenjamin 10 месяцев назад

    Always on point sir God bless for your impactation

  • @HelloBillyyu
    @HelloBillyyu 5 месяцев назад

    Hi I have just watched the video. Great work! Many thanks. Can I explore another approach here? We could find the Maclaurin series of e^h and it is be 1 + h + h^2 / 2 … then (e^h - 1) / h = 1 + h^3/2 + … then the limit of this is 1 if h goes to 0. This method is generally applicable to many ‘nasty’ limit calculations. Happy to chat. Cheers!

    • @PrimeNewtons
      @PrimeNewtons  5 месяцев назад +1

      Yes, that's an option. However, this video was to highlight first principles.

  • @kemumawhitney5439
    @kemumawhitney5439 2 года назад +1

    Your classes are enjoyable

  • @tcmxiyw
    @tcmxiyw Год назад +4

    I think your explanations are beautiful, but when you say something like “the limit of the function is the function of the limit”, please justify it by saying “because the function is continuous”. It is interesting to note that the derivative of f(x)=e^x at any point can be found once we know f’(0).

  • @muwememwanza3815
    @muwememwanza3815 3 года назад +2

    Great video just learned something new

  • @sergiolucas38
    @sergiolucas38 2 года назад +1

    Great video, you're very didactic and your letters are quite pretty as well, thank you :)

  • @znhait
    @znhait Год назад +1

    This is excellent work. I'm wondering if there isn't an easier way...or just a more obvious to come up with this limit. Otherwise, the definition of e could have been used a lot earlier.

  • @idolgin776
    @idolgin776 Год назад

    It was really cool when the exponential definition of e popped out. Never seen such manipulation before!

  • @nemo5619
    @nemo5619 Год назад

    Fabulous video, hats off!

  • @Aferz
    @Aferz Год назад +1

    Thank you SOOOOOO MUCH! You made me understand it and now I feel so good and so YEEEEEES
    YEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEES

    • @PrimeNewtons
      @PrimeNewtons  Год назад

      ❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️

  • @tfdtfdtfd
    @tfdtfdtfd 2 года назад +2

    Excellent video avoiding the unelegant definition of e as the "eh-1" limit......we should probably add a few technical details about the existence of limits when you split into products, ratios, swap order of ln and lim.....these generally hold true here due to continuity

    • @PrimeNewtons
      @PrimeNewtons  2 года назад +3

      Thanks for the extra notes. Appreciated!

  • @shcottam
    @shcottam 2 года назад +1

    Dude, this is pretty sick

  • @masoudhabibi700
    @masoudhabibi700 Год назад +1

    Thank for one more time.... master

  • @Bob-sq7ev
    @Bob-sq7ev 9 месяцев назад

    Thank you sir this helped me a lot ❤❤❤

  • @barthennin6088
    @barthennin6088 2 года назад +3

    It appears to be a circular argument. ln(e^x)=x and e^ln(x)=x

    • @PrimeNewtons
      @PrimeNewtons  2 года назад +3

      Lol. That's what a lawyer would say. In mathematics, they are called inverse functions.

  • @yigitrefikguzelses291
    @yigitrefikguzelses291 Год назад +1

    When we are dealing with lim n->0 1/(ln(1+n)^(1/n) isn't this expression undefined because we have 1/n in the expression. I will be so happy if you can help me

    • @PrimeNewtons
      @PrimeNewtons  Год назад +3

      n is not 0 yet. We are just approaching 0. So the function is not undefined and you should not plug in zero into the function because then it will be erratic. Try sketching that in desmos and see what happens as you approach zero. 😉

    • @yigitrefikguzelses291
      @yigitrefikguzelses291 Год назад

      @@PrimeNewtons yeah its say approxirametly 2.718 so it's e but aren't we getting different result while approching from negative infinity,(by the way thank you for your respond)

  • @komalshah1535
    @komalshah1535 Год назад

    Fantastic sir!

  • @JulesMoyaert_photo
    @JulesMoyaert_photo Год назад

    Nice demo!

  • @dr.rahulgupta7573
    @dr.rahulgupta7573 2 года назад +2

    Sir. Can we use the definition of e^h to simplify ( e^h --1)/h and then take the limit ?

  • @muzza881
    @muzza881 4 месяца назад

    I like to use the series expansion of exp(x) for this. Then exp(x+h) = 1+(x+h)+(x+h)^2/2! +...........
    Exp(x+h)-exp(h) term by term gives 1-1 + x+h-x + 0.5(x^2+2hx+h^2-x^2) + ........
    Subtracting, dividing by h, and taking the limit gives us back exp(x).
    I suppose you can claim that the definition of the Taylor series already used derivatives to all orders of exp(x).

  • @the_n_ecromancer
    @the_n_ecromancer 10 месяцев назад

    "you see that? That makes life a lot easier"😂😂😂

  • @K-drama-LegendKing
    @K-drama-LegendKing 2 года назад +2

    thanks for not using circular logic this makes so much sense the video is amazing, i would love to check your other videos although i know the the derivatives but the way you explained this one im excited to see the other derivatives

  • @12388696
    @12388696 2 года назад +1

    Well done

  • @_cran
    @_cran Год назад

    I know you mostly do calc but can you make a video about fourier series/transform-inverse transform and a video about laplace transform-inverse transform? It'd be pretty educating I think since I just know the logic of it's graph I know it's formula but I don't understand how or why it works to just integrate something with e^-ikx then re-integrate it with e^ikx shapes the function in a different way

  • @JessicaShaw-ym4vc
    @JessicaShaw-ym4vc Год назад

    Hi! where does the definition of e in terms of n come from? thank you. your video was great :)

  • @馬瑞基
    @馬瑞基 3 года назад +2

    It is so helpful

  • @ΛαζαροςΙωαννιδης-φ5υ
    @ΛαζαροςΙωαννιδης-φ5υ 9 месяцев назад

    Bravo. Perfect.

  • @durjoysaha2896
    @durjoysaha2896 8 месяцев назад

    That helps a lot❤

  • @paulwood3460
    @paulwood3460 8 месяцев назад +1

    Excellent proof. 👏👏👏👍👍 just one criticism..before starting the the proof of derivative e^x just state the fact that (lim n->0 (1+n)^1/n) = e
    Mathematics is simply wonderful.

    • @robertveith6383
      @robertveith6383 7 месяцев назад

      The exponent, 1/n, must be inside grouping symbols: (1 + n)^(1/n)

    • @paulwood3460
      @paulwood3460 7 месяцев назад

      @@robertveith6383 surely you mean (1+n)^1/n 😀

  • @ukidding
    @ukidding Год назад +1

    you have v nice writing

  • @kaboflotv6455
    @kaboflotv6455 Год назад +1

    What about y=sin(×+1) from first differentiation??kindly asking

    • @PrimeNewtons
      @PrimeNewtons  Год назад

      I have to a video for sin x. Use the same idea.

    • @PrimeNewtons
      @PrimeNewtons  Год назад

      Same exact process. You'll get cos(x+1)

  • @hypothesisnyc916
    @hypothesisnyc916 2 года назад +3

    Your teaching style is great but it bugs me that you're using implication symbols as though they are equal signs. For students to know the difference between "equals" and "implies" makes a big difference in their understanding of proofs.

    • @PrimeNewtons
      @PrimeNewtons  2 года назад +1

      I completely agree. I promise to never do that again. Could you suggest a replacement for doing my transition without using the implication symbol.

  • @geraldomelo2751
    @geraldomelo2751 Год назад

    The l'hopital theorem can also be applied.

  • @punditgi
    @punditgi 2 года назад +2

    My first principle is to always watch Prime Newtons! 🥰

  • @patelharsh5133
    @patelharsh5133 3 года назад +3

    Thanks sir

  • @reddottgamer3047
    @reddottgamer3047 2 года назад +3

    Finnally earth become a livable place.

  • @Rayglobster
    @Rayglobster 2 года назад +1

    This is perfect

  • @atri5280
    @atri5280 2 года назад +2

    ॐनमःशिवाय 🙏

  • @nievalesterloydp.7399
    @nievalesterloydp.7399 Год назад

    Ang angas

  • @FelixShiri
    @FelixShiri Месяц назад

    what if I use L'hospital at stage lim as h->0 ( e^h -1)/h

  • @TofaraRungano
    @TofaraRungano Год назад

    Culculas simplified ❤

  • @Pauladam2216
    @Pauladam2216 3 года назад +2

    Nice

  • @shivankargupta6675
    @shivankargupta6675 Год назад +1

    😍😍😍😍😍

  • @ThenSaidHeUntoThem
    @ThenSaidHeUntoThem 3 года назад +1

    Coool!

  • @СергейКовалев-т1д6м
    @СергейКовалев-т1д6м 9 месяцев назад

    👍👍

  • @tomvitale3555
    @tomvitale3555 11 месяцев назад

    We've been saved from destruction and made the world a better place to live! 😁 Excellent description!

  • @mazenzidieh
    @mazenzidieh Год назад

    Thanks alot

  • @anestismoutafidis4575
    @anestismoutafidis4575 Год назад

    It stays as it is= e^x, except for x we put numbers ( N○ - C)

  • @CarolineSikamoi-rh7iv
    @CarolineSikamoi-rh7iv Год назад +1

    Encourage though small writings make them more clear atleast

  • @GiftMlinde
    @GiftMlinde 6 месяцев назад

    Eeeee sir ❤❤❤❤

  • @catnip2906
    @catnip2906 7 месяцев назад

    Dear Sir. Thanks for the clarity. I was blind but now I see.

  • @sochegeorge7962
    @sochegeorge7962 Год назад

    Can someone please explain the move at 9:32

    • @sochegeorge7962
      @sochegeorge7962 Год назад

      Should have added if n = 23, (1/23)*ln(24) is NOT equal to Ln(24)^(1/23)

  • @anish3171
    @anish3171 9 дней назад

    love being taught maths by kanye west's brother

  • @justinnwachukwu2054
    @justinnwachukwu2054 Год назад +1

    Write your number on the board. I appreciated your teaching style

    • @PrimeNewtons
      @PrimeNewtons  Год назад +1

      My guy, I no fit write my number for blackboard na! Wetin be dat?