the fact, again (with a definition of e)

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blackpenredpen

blackpenredpen

Күн бұрын

By l'hopital's rule, • THE FACT
The other def. of e • what is e, and the der...
I call this limit "the fact" with my students, so we can refer to this easily whenever we need to calculate such limit. ,
Limit as x goes to infinite, (1+a/x)^(bx), using definition of e,
Limit of (1+a/n)^(bn) as n goes to infinity,
Using definition of e to calculate limits,
limit of (1+1/x)^x,
www.blackpenredpen.com,
blackpenredpen,
math for fun,

Пікірлер: 50
@azamingxzc9570
@azamingxzc9570 7 жыл бұрын
I love your videos, I am not in calculus yet, precal and right now it's just algebra review, but your videos are still interesting. I don't know what derivative means or is, or integration, but I find it fun how do you do algebra and rules of those things to solve equations.
@TrinoElrich
@TrinoElrich 7 жыл бұрын
Azaming Xzc you'll get there eventually, man. Fun stuff 👌
@David-xq3bg
@David-xq3bg 5 жыл бұрын
Integration is basically chopping something up into infinitely small pieces and adding them together. I didn't realize this until halfway through Calc III, wish I realized this long long ago. hope it helps one day :)
@markgraham2312
@markgraham2312 4 жыл бұрын
Your two videos (lessons) on The Fact are great! Thank you!
@blackpenredpen
@blackpenredpen 4 жыл бұрын
Glad to hear. Thank you.
@rexevan6714
@rexevan6714 7 жыл бұрын
I just realize that the word "blackpen" isn't even black, but you got the redpen correctly (look at your profile picture) :P
@dannyspeagle10
@dannyspeagle10 7 жыл бұрын
This is on of my most favorite proofs from you.
@mangeshmalgi279
@mangeshmalgi279 7 жыл бұрын
Very lucid explanation Thanks
@sherwan2
@sherwan2 Жыл бұрын
Thanks for all these great videos!
@user-wu8yq1rb9t
@user-wu8yq1rb9t 3 жыл бұрын
Teacher ... I love your old videos too. And honestly, sometimes I love them even more than Newest one. There is a difference between your old videos and new ones. If I was on your shoes, i tried to find it because it's very very important (I know what it is!) Even when I'm in the bad mood, I watch your videos, because their change my mood ... Therefore your channel is so important to me and ... I love you teacher ❣️)
@Sprajt
@Sprajt 3 жыл бұрын
Wow this is a great explanation of substitution! It finally makes sense to me. Thanks!
@allisonstenz2287
@allisonstenz2287 5 жыл бұрын
whyyyyy did the professor never mention this ??!! You saved my life thank you
@lanasurkis8768
@lanasurkis8768 2 жыл бұрын
your videos are very good and have a wide message thank you
@markkennedy9767
@markkennedy9767 2 жыл бұрын
Hi can the definition of e also be given as the limit as x goes to minus infinity of this expression. Or is there a restriction that it has to be as x goes to plus infinity. The reason I ask is I'm trying to recall if the equivalent definition of e where x goes to zero is a one sided or two sided limit to zero. In other words, does that definition only have X going to zero from the positive side and not the negative side. Surely it's a two sided limit isn't it in the definition of e. Can you refresh my memory? Cheers
@wonghuaixin6681
@wonghuaixin6681 3 жыл бұрын
Thank you!! your solution are so easy to understand !!!!
@yogevsimonovich5887
@yogevsimonovich5887 7 жыл бұрын
Can you do a video proving or explaining the chain rule? Love your vids (:
@brubsi9658
@brubsi9658 4 ай бұрын
where can i find the proof of eulers number definition but without using lhopitals rule
@bbsonjohn
@bbsonjohn Жыл бұрын
how do you prove for complex a and b
@Cloud88Skywalker
@Cloud88Skywalker 6 жыл бұрын
Hi! You take the limit of the power as the power of the limit BECAUSE "the power" is a continous function. But that's not generally the case. Negative powers are typically discontinous. Take for example x^(-1). Its discontinous, specifically at x=0. And it doesn't even have a limit there. So... does this work because it's miraculously avoiding the discontinuities?
@angelmendez-rivera351
@angelmendez-rivera351 6 жыл бұрын
Eric Ester The only place at which x^p for any real-valued p and any real-values x is discontinuous is at x = 0, provided that x^p is allowed to be complex-values. This works because we know that x is not 0 in the situation, since x = e by the limit definition of e. For all positive x, x^p is always continuous if p is real-valued.
@khaalidmaxamuud3581
@khaalidmaxamuud3581 4 жыл бұрын
Absolutely you explained it easily way
@skltfz4997
@skltfz4997 Жыл бұрын
i want to know why e^1 = limit of n to inf (1+1/n)^n
@samueldeandrade8535
@samueldeandrade8535 11 ай бұрын
I have to talk some sh1t here. The definition e := lim (1+1/n)ⁿ is NOT just a definition. It is ESSENTIALLY THE definition of e. Because it is the original definition. I can't understand why people don't recognise that.
@katiatzo
@katiatzo Жыл бұрын
Thank you Sir!
@sinom
@sinom 7 жыл бұрын
Wait... Again again?
@blackpenredpen
@blackpenredpen 7 жыл бұрын
Sinom yes. This is an easier way..
@Craznar
@Craznar 7 жыл бұрын
Easier ways always worth it. The journey is the best part :)
@materiasacra
@materiasacra 7 жыл бұрын
It is not just another, possibly easier, way. Slowly the logical structure becomes a little more explicit: what are definitions, and what is derived from them. Early teaching is often vague on this, pointing out 'disjointed' connections to give students an intuitive grasp. Formal structure comes later.
@guliyevshahriyar
@guliyevshahriyar Жыл бұрын
Thanks a lot teacher
@dogbiscuituk
@dogbiscuituk 7 жыл бұрын
BlackPenTransparentPen ;-)
@steve2817
@steve2817 5 жыл бұрын
lim x->inf (1+π/x)^ix = -1 Complekzical limit
@GusPintarKalianGoblok
@GusPintarKalianGoblok 6 жыл бұрын
I got e^(ab) also. YAY 😊😊😊
@kijstanley2798
@kijstanley2798 5 жыл бұрын
I love this Sir
@ivana5263
@ivana5263 4 жыл бұрын
You're an angel!
@beezball38
@beezball38 7 жыл бұрын
doesn't that other definition of e only converge when we approach 0 from the right?
@angelmendez-rivera351
@angelmendez-rivera351 6 жыл бұрын
Chris Beser No, it converges from the negative ray of the axis as well. This can be seen by the fact that the negative from the 1/u can be factored away, and we obtain a product (-1)^u*1/|u|, which limits with u -> 0-. Yet this means (-1)^u -> 0-, so asymptotically, it is equivalent with the limit that has u -> 0+, so the limit exists.
@JordHaj
@JordHaj 6 жыл бұрын
6:45 blackpen.exe stopped working
@davidseed2939
@davidseed2939 7 жыл бұрын
Why do you make it so complicated, you could do this in five lines. 1) question . Y = lim x-> ( 1+ a/x) ^bx 2) definition of e using t 3) raise this equation to the power z Y = e^z 4) substitute for t, 1/t= a/x. ; Zt = bx. So z= ba 5) Y= e^ba Example a=-1/2. ; b=4. Substitute in 5). Y= e^-2
@angelmendez-rivera351
@angelmendez-rivera351 6 жыл бұрын
David Seed That is not rigorous enough. You cannot substitute backwards like that. Also, he did do it in essentially five lines.
@aiapihud4344
@aiapihud4344 2 жыл бұрын
out of curiosity, if the lim x->inf (1+1/x)^x = e, then why does it equal 1 when x > 9.0072 x 10^15?
@James2210
@James2210 2 жыл бұрын
Floating point errors
@aiapihud4344
@aiapihud4344 2 жыл бұрын
@@James2210 what? explain in depth I've taken calc1 n that's it
@gabe9388-g5g
@gabe9388-g5g 3 жыл бұрын
my guy
@koenth2359
@koenth2359 6 жыл бұрын
陈露 !!
@Whatdothenumbersmean
@Whatdothenumbersmean Жыл бұрын
mashallah
@SavageLevel-ez1sx
@SavageLevel-ez1sx 4 жыл бұрын
supreme :0
@ahmednasr6171
@ahmednasr6171 4 жыл бұрын
it still helpful
@sunilathinagaram4441
@sunilathinagaram4441 5 жыл бұрын
u r living srinivasa ramanujan
@longgguterres-pn2jx
@longgguterres-pn2jx Жыл бұрын
How to solve lim(5n-2/5n+3)^3n
@Hogojub
@Hogojub 7 жыл бұрын
nice
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