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how to solve sin(x)=i? 

blackpenredpen
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Learn how to solve this complex impossible-looking trig equation sin(x)=i. Of course, we need to use Euler's formula and the complex definition of sine.
sin(sin(z))=1 • Math for fun, sin(sin(...
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2 дек 2018

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Комментарии : 369   
@blackpenredpen
@blackpenredpen 10 месяцев назад
sin(z)=2, ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-3C_XD_cCeeI.html sin(sin(z))=1 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8dp35ZhUr_o.html
@sergiolozavillarroel3784
@sergiolozavillarroel3784 5 лет назад
I solved this very easily: sin(z)=i z=arcsin(i) Easy isn't it?
@davidawakim5473
@davidawakim5473 5 лет назад
The point is to figure out what arcsin(i) is through algebraic manipulation.
@crosisbh1451
@crosisbh1451 5 лет назад
Did you doing in your head... without prompting‽‽
@seangrand3885
@seangrand3885 5 лет назад
CrosisBH what ._.
@Abdega
@Abdega 5 лет назад
Future mathematician right here ☝️
@R1ckr011
@R1ckr011 5 лет назад
@@crosisbh1451 he is horribly UnFun in the explanation process
@PaddedShaman
@PaddedShaman 5 лет назад
i don't need to be on the bottom if i don't want to
@poppo20202020
@poppo20202020 5 лет назад
That's what she said!
@cdeyng
@cdeyng 5 лет назад
HAHA, that was witty though. XD
@janv.8538
@janv.8538 5 лет назад
_top comment_
@userBBB
@userBBB 5 лет назад
when did he say this?
@dinamosflams
@dinamosflams 4 года назад
That's what Lilith said ( ͡° ͜ʖ ͡°)
@pelegmichael5489
@pelegmichael5489 5 лет назад
8:00 "pi is an integer". I am personally offended.
@Albkiller22
@Albkiller22 5 лет назад
But he wrote only n is an integer so was not wrong
@PaddedShaman
@PaddedShaman 5 лет назад
π ∈ ℤ
@jabir5768
@jabir5768 5 лет назад
well pi is an integer isnt it?
@blackpenredpen
@blackpenredpen 5 лет назад
Sarcastic Name I feel I have to make a public apology now Bc of that. : )
@kingbeauregard
@kingbeauregard 5 лет назад
We are young Heartache to heartache We stand No promises No demands Pi is an integer Whoo
@VJZ-YT
@VJZ-YT 5 лет назад
you are the only person in this world that makes math look fun. well done
@blackpenredpen
@blackpenredpen 5 лет назад
VJZ thanks!!!
@branthebrave
@branthebrave 5 лет назад
Definitely not the only one
@VJZ-YT
@VJZ-YT 5 лет назад
@@branthebrave who else?
@branthebrave
@branthebrave 5 лет назад
@@VJZ-YT Definitely a lot o teachers out there at any level that do that. Math always looks fun to me, so that doesn't really matter. You're probably asking for other youtube channels, so really any of the popular ones sometimes do like numberphile, 3blue, mathologer, standupmaths, but it depends what you call "fun," like maybe you mean really interesting. Think twice does that.
@Mexa2105
@Mexa2105 5 лет назад
I get impressed when you use the euler's identity by using as well the logaritms rules good video man
@dremr2038
@dremr2038 2 года назад
Same , he used the perfect technique to teach that concept
@hamez1324
@hamez1324 5 лет назад
sin inverse both sides -> z= sin^-1 (i) ez
@joshuamason2227
@joshuamason2227 5 лет назад
@@simpletn r/whoosh
@alexting827
@alexting827 4 года назад
BAD NOTATION XDD
@cwo12cw
@cwo12cw 5 лет назад
One answer is the negative imaginary natural log of the silver ratio. *how. Cool. Is. Thaat.*
@blackpenredpen
@blackpenredpen 5 лет назад
Clemente Wacquez : )))))
@alansmithee419
@alansmithee419 5 лет назад
Maths does weird things with seemingly unrelated areas sometimes.
@98danielray
@98danielray 5 лет назад
has to do with the quadratic equation that appeared
@nazishahmad1337
@nazishahmad1337 5 лет назад
Silver ratio what's that I've heard of golden ratio only
@shoobadoo123
@shoobadoo123 5 лет назад
alan smithee *math
@iansamir18
@iansamir18 3 года назад
Easy solution: sin(z) = i, so cos(z) = sqrt(2) by sin^2 + cos^2 = 1. Therefore, e^(iz) = cos z + i sin z = sqrt(2) + i(i) = sqrt(2) - 1, and z = -i ln(sqrt2 - 1) as desired.
@user-gp5zr9wb4z
@user-gp5zr9wb4z 5 месяцев назад
cos(z) = ±√2
@m_riatik
@m_riatik 5 лет назад
i discovered you from the sin(z) = 2 video. i remember a lot of people were fighting in the comments because you said "conplex axis"
@blackpenredpen
@blackpenredpen 5 лет назад
Muriatik yea lol
@themeeman
@themeeman 5 лет назад
F
@chatherinehu3804
@chatherinehu3804 5 лет назад
Hahahah I think they pay the wrong attention
@david-yt4oo
@david-yt4oo 5 лет назад
4:10 you always make really interesting videos, and some .real. good puns
@hazza6915
@hazza6915 5 лет назад
For logarithm to be bijective you need to specify which theta you are taking and which half line you are removing also
@chatherinehu3804
@chatherinehu3804 5 лет назад
I love your way of making maths fun , hoping to be the same person like you .
@blackpenredpen
@blackpenredpen 5 лет назад
Thank you!!
@prollysine
@prollysine 4 года назад
Szerintem ez totál elméleti, talán csak elméleti matek szempontból érdekes, de sok apró lépés eszembe jutott. Nagyon jól tanítasz, minden részletet bemutatsz gratulálok !
@stigastondogg730
@stigastondogg730 4 года назад
Love this dudes passion for math!
@enisheadpay
@enisheadpay 5 лет назад
If you want a single formula you could rewrite the final answer as arcsin(i)=-i*ln(sqrt(2)+(-1)^(k+1))+k*pi for integer values of k.
@quitecomplex6441
@quitecomplex6441 5 лет назад
I just stumbled along this problem the other day and I solved it. I came on here to check my answers. Very cool problem indeed.
@andrecruzmarquez645
@andrecruzmarquez645 5 лет назад
"You got to do more work to please people" ...
@admancr2823
@admancr2823 Год назад
I am absolutely passionated about complex numbers... It is just completely different from anything I have learned for 19 years of my life, sometimes is just crazy. Yet it is so useful that we use these numbers in electricity, quantum mechanics, Riemann's hypothesis which is the biggest mystery in Maths. Just amazing. Thank you for your work sir.
@Matthew-tu2jq
@Matthew-tu2jq 5 лет назад
This is awesome i love the content you make ❤️
@dhay3982
@dhay3982 5 лет назад
Now do the formula Sin(z)=a+bi
@shre6619
@shre6619 5 лет назад
Z is just sin^-1(a+ ib)
@antimatter2376
@antimatter2376 5 лет назад
@@shre6619 And what is the inverse sin of a complex number?
@thanoskalamaris3671
@thanoskalamaris3671 5 лет назад
@Seife Zwei you take the formulas of sin-1(I) and switch i with a+bi
@antimatter2376
@antimatter2376 5 лет назад
@@thanoskalamaris3671 That's not how math works
@themanagement69
@themanagement69 5 лет назад
You can write any real number in a+bi form.
@pedrocastilho6789
@pedrocastilho6789 5 лет назад
You can also do by saying that e^iz=cos(z)+isin(z) Since cos^2+sin^2=1 Cos^2+(i)^2=1 Cos^2-1=1 Cos^2=2 Cos(x)=+-sqrt(2) Using that you have that e^iz=+-sqrt(2)-1 The rest is the same as the video :)
@24_santanurath56
@24_santanurath56 2 года назад
seriously i have fun by this video teaching style,This video is amazing
@enclave2k1
@enclave2k1 2 года назад
" _i_ don't have to be on the bottom if _i_ don't want to" Brilliant pun and very useful.
@MrKhan-dw9vh
@MrKhan-dw9vh 5 лет назад
I am missing "Blackpenredpen Yay!"
@noahp4589
@noahp4589 3 года назад
i think a clever way to do it without knowing the complex form of sin would be by sin(z)=i sin²(z)=-1 1-cos²(z)=-1 cos²(z)=2 cos²(z)=plus or minus sqroot 2 then by reemplazing in euler's formula e^iz=cos(z)+isin(z) e^iz=plus or minus sqroot 2 +i² i really enjoyed the video thanks for being an awesome teacheeeer
@krishabm1
@krishabm1 5 лет назад
None of your videos are possible without e.... XD
@blackpenredpen
@blackpenredpen 5 лет назад
: )
@gelatinaworld
@gelatinaworld 5 лет назад
You need a high iq to get the E
@nuklearboysymbiote
@nuklearboysymbiote 4 года назад
@@gelatinaworld but im a silly man with a small
@JivanPal
@JivanPal 4 года назад
@@infernocaptures8739, ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-bZivCw3bB6w.html
@MrBeen992
@MrBeen992 4 года назад
8:04 "You write down where n is Z so people know you are cool" LOL
@Iamnotyou29
@Iamnotyou29 3 года назад
I get fun to look your math problems. Thnx sir🙂🙂
@dr.rahulgupta7573
@dr.rahulgupta7573 2 года назад
Excellent presentation ! Vow !!
@davidawakim5473
@davidawakim5473 5 лет назад
This video was great :D
@user-td6pl6wk6s
@user-td6pl6wk6s 3 года назад
Thank you so much
@rezamohammadyousefi3317
@rezamohammadyousefi3317 2 года назад
Wow its very useful for me...tanku for that
@gregoriousmaths266
@gregoriousmaths266 4 года назад
this is ez for me now, but it wouldnt be if it werent for ur vids thank u so much
@tylertorsiello8450
@tylertorsiello8450 3 года назад
this guy is my spirit animal
@backyard282
@backyard282 4 года назад
10:15 You can't call that z=arcsin (i), because arcsin is a function so it can't have infinitely many values, it gives a "principled" angle, while the set of all solutions to sin z = i include arcsin + 2pi*n and pi - arcsin + 2pi*n. The same way how the square root function gives you the principal root, and the set of roots are +/- the square root function.
@soumyachandrakar9100
@soumyachandrakar9100 5 лет назад
Would you mind doing a video on Fermat's Little Theorem?
@abdellh8079
@abdellh8079 3 года назад
Actually it is interesting , great job , keep going ,
@alanwolf313
@alanwolf313 5 лет назад
Hello RPBP i really like your videos and I need some help. I was doing some math for fun the other day and tried to solve the integral of the xth root of x (or xˆ(1/x)) dx. How should I tackle this problem?
@magnuschanduru6173
@magnuschanduru6173 5 лет назад
Nice way of teaching..
@DrDirtyHarry
@DrDirtyHarry 5 лет назад
The two general solutions look very similar. Is there a correspondence on the complex plane?
@michael161
@michael161 Год назад
Math is so beautiful and helpful in our life.❤️❤️❤️
@AndDiracisHisProphet
@AndDiracisHisProphet 5 лет назад
8:05 pi is an integer? Almost as good as three is smaller than two^^ Also, Sin(z)=2 was cooler, imho.
@blackpenredpen
@blackpenredpen 5 лет назад
Lol!!! Yup I still remember that one too!! Btw, the time mark should be 8:00
@AndDiracisHisProphet
@AndDiracisHisProphet 5 лет назад
@@blackpenredpen Oh. I BPRP'uped the time stamp. Do you remember which video that was?
@blackpenredpen
@blackpenredpen 5 лет назад
AndDiracisHisProphet log_2(3) vs log_3(5)
@AndDiracisHisProphet
@AndDiracisHisProphet 5 лет назад
@@blackpenredpen such a trauma, that you still remember^^
@blackpenredpen
@blackpenredpen 5 лет назад
AndDiracisHisProphet lol!! So did you!
@muse0622
@muse0622 5 лет назад
I Love Math. Blackpen Redpen YAY
@user-co6rg9jt9x
@user-co6rg9jt9x 5 лет назад
I love this "This like that"
@rainbow-cl4rk
@rainbow-cl4rk 5 лет назад
I have question: e^(iz)=+-sqrt(2)-1 =cos(z)+isin(z) But sin(z)=i =cos(z)+ii =cos(s)-1 Cos(z)-1=+-sqrt(2)-1 Cos(z)=+-sqrt(2) Arccos(cos(z))=arccos(+-sqrt(2)) Z=arccos(+-sqrt(2)) It is correct?
@thesame7423
@thesame7423 2 года назад
Yeah but you still have to do more work for the arccos, cuz it's domain is only [-1;1] and sqrt(2)>1/-sqrt(2)
@No_hope_No_fear
@No_hope_No_fear 5 лет назад
Bprp: "Okay, thanks for watching" *almost dies laughing
@blackpenredpen
@blackpenredpen 5 лет назад
LOLLLL
@alansmithee419
@alansmithee419 5 лет назад
Does anyone know of an app I could get for an android phone that plots complex number equations on graphs?
@renardtahar4432
@renardtahar4432 5 лет назад
vous etes formidable!
@manuelepedicillo864
@manuelepedicillo864 5 лет назад
I want number theory videos 😭😭
@jakubfrei3757
@jakubfrei3757 5 лет назад
Excatly
@gian2kk
@gian2kk 5 лет назад
Escatly
@sergiolozavillarroel3784
@sergiolozavillarroel3784 5 лет назад
Persicely
@srpenguinbr
@srpenguinbr 5 лет назад
with complex integers!
@professorpoke
@professorpoke 3 года назад
You should watch Micheal Penn on RU-vid, for number theory problems.
@quantumcity6679
@quantumcity6679 5 лет назад
thank's for watching...... 😁😘
@andresidl
@andresidl 2 года назад
“i don’t like to be on the bottom” hahaha I see what you did there
@anthonywong1781
@anthonywong1781 5 лет назад
Are you sure you can just invert sin without specifying the domain and range for this question? The formal definition for the inverse of sin is for every x in [-π/2, π/2] , y in [-1,1] , arcsin(y) = x if and only if y = sin(x) though.
@nullanon5716
@nullanon5716 5 лет назад
If we plugged in the first solution into the z of the second solution, wouldn’t that make pi*(2m+1) = 0?
@francis6888
@francis6888 5 лет назад
"2 screw" Gotta love subtitles.
@sgrass471
@sgrass471 5 лет назад
for the second answer wouldnt the pi and the 2*pi*m term add together giving us pi*(1+2m)? or in other words pi*q where q is an odd number? by the way love your videos
@af8811
@af8811 5 лет назад
The important lesson from this, is : "Keep people in peace by not to do logarithm of negative numbers. Just don't do that and even touch it" (Prof. Steve) 😆😆😆😆😆👍👍👍👍👍
@blackpenredpen
@blackpenredpen 5 лет назад
: ) #SteveIsMyStageName
@af8811
@af8811 5 лет назад
Please don't be mad Professor ☺☺. I was joking. He he he he... Cause math is fun, isn't it Professor ??? 👍😊👍
@blackpenredpen
@blackpenredpen 5 лет назад
@@af8811 Oh no, I wasn't mad at all. I just wanted to put that harsh tag whenever people comment "steve" : )
@af8811
@af8811 5 лет назад
@@blackpenredpen :') i thought it's your real name, Professor.
@madaaz6333
@madaaz6333 5 лет назад
There may be a problem in this case. According to Wikipedia (complex logarithm) the property Log (z1 z2) = Log (z1) + Log (z2) is not generally valid when there is a negative number. What do you think about it?
@Reallycoolguy1369
@Reallycoolguy1369 2 года назад
Before watching the video, I tried this problem, and when I got to that step, I used the polar coordinate definition of the complex number (z=a+bi, z= r*cos[theta] + i*r*sin[theta]), then applied euler's formula (z=r*e^i[theta]), then took the natural log (ln(z)=ln(r) + i*[theta]). In this case r is |-1-sqrt(2)| and since this is a negative real number, on the complex plane the angle theta would be pi. So you end up with i*z=ln(1+sqrt(2))+i*pi, and then it's the same steps as the video. This doesnt require the product property of logarithms and I got the same answer, so I think we are good here. BPRP shows exactly what I'm describing in the sin(z)=2 video.
@viletomedoze5036
@viletomedoze5036 5 лет назад
Best part of the video " i don't need to be at the bottom if i don't want to"
@yugeshkeluskar
@yugeshkeluskar 5 лет назад
Can you generalize it for sin(?)=a+bi
@shoopinc
@shoopinc 5 лет назад
Yeah, ill give it a try
@shoopinc
@shoopinc 5 лет назад
@@Tom-qz8xw I've worked it down to a formula where you can input a and b and have it pop out the answer. But I must have made an algebra mistake somewhere because its slightly wrong. For the case in the video it gives me a value where I take the sin and it gives 1.5*i rather than i. So I'll do the derivation again and fix it.
@sergiolozavillarroel3784
@sergiolozavillarroel3784 5 лет назад
@@shoopinc Done yet?
@RendeiRotMG
@RendeiRotMG 3 года назад
if you still need it. It's sin(z)=pi/2-i*ln(z±sqrt(z^2-1))
@factsheet4930
@factsheet4930 5 лет назад
My professor told me that it is possible to solve for z in the equation |z|=-1 Wolfram Alpha couldn't do it, can you make a video about it, if it is possible?
@jessehammer123
@jessehammer123 5 лет назад
Fact Sheet I think your professor is wrong. In the real number set, there’s obviously no number that fulfills this. In the complex world, all complex numbers have positive magnitude. In the quaternion world, all quaternions have positive magnitude. Et cetera, I think. But I’m just a sophomore in high school, so what do I know?
@zuccx99
@zuccx99 5 лет назад
It's impossible because it's undefined just like 1/x when x is 0.
@factsheet4930
@factsheet4930 5 лет назад
I mean probably not as the distance definition but as square root of x to the power of 2 And yes Wolfram Alpha will say there is no solution but it also says that for x^(1/3)=-2, while clearly - 8 is the solution.
@98danielray
@98danielray 5 лет назад
depends on how norm is defined. is this the usual norm?
@8bit_pineapple
@8bit_pineapple 5 лет назад
Okay, so for the real numbers |x| is just defined as |x| = { x if x ≥ 0 {-x if x < 0 i.e. throw away the minus if there is one. For other numbers like the: Complex, Quaternions, Octonions, etc The ||z|| function is the distance from 0 to z. As such, you won't find an example where ||z|| < 0, in any of these sets of numbers. Distance functions map to values ≥0 as part of their definition. But supposing ... You had your own set of numbers "😂", Then you define a function f : 😂 → ℝ , where f(z) = -2 for some z∈😂 Everyone would think you're an ass if you wrote "Let |z| = f(z) when z∈😂" By all means you could... it's your mathematics... But... my recommendation would be for you to extend |z| with a new function "😊" And just put: 😊(z) = { |z| if z∈ ℝⁿ { f(z) if z∈😂 That way everyone will be happy with your notation.
@ExzeneriteXll3492
@ExzeneriteXll3492 3 месяца назад
By writing 2π, it is aproximating aproximated tau or 6.28
@roc6596
@roc6596 4 года назад
I learned complex numbers for high school, still though, didn't see any of this e number and all, is it only for calculus at a university? I'm from Brazil so I don't know if it's just cause here we don't have this for HS curriculum
@haninyabroud7810
@haninyabroud7810 5 лет назад
Thx i ♡ maths
@Bicho04830
@Bicho04830 5 лет назад
Yep but note that (1+√2)=(-1+√2)^(-1) (reader exercise) So ln(1+√2)=-ln(-1+√2), and therefore we can wtite it as: z=nπ +((-1)^n)ln(-1+√2)
@gilber78
@gilber78 3 года назад
wouldn't the full answer just by -i*ln(1+sqrt(2)) + pi*n since both answers are the same just offeset by pi and they both have the 2pi factor?
@ryanguenthner823
@ryanguenthner823 3 года назад
"We have to do more work to appease people." Man, I fucking felt that. Great video.
@DrQuatsch
@DrQuatsch 5 лет назад
I would like it more if you had taken sin(z) = i/2. -1+sqrt(2) and 1+sqrt(2) are not as nice as the golden ratio in your answer.
@maxchatterji5866
@maxchatterji5866 5 лет назад
Hey BPRP, I have an Oxford maths interview in a week. Are there any cool maths tricks I should know about which would blow the interviewer away?
@blackpenredpen
@blackpenredpen 5 лет назад
Hmmm, I am not sure about math tricks, especially they should be the finest math people in the world. If I have to do it myself, I will definitely show them how to do math with blackpen and redpen in one hand. Best luck to you!!!! Keep me updated. I would love to hear how it goes!
@lilysowden4035
@lilysowden4035 5 лет назад
I have a computer science interview next week as well!
@trueriver1950
@trueriver1950 5 лет назад
Prove there are no boring positive integers. 0 1 is not boring because it is the identity for multiplication 2 is not boring because it is the smallest prime 3 is not boring because it is the closest prime to the previous 4 is not boring because it is the smallest composite 3 5 and 7 are not boring because they form the smallest value series of primes in arithmetic progression 6 is not boring because it is the first number with distinct prime factors This proof IS becoming boring so can we generalise it? Reductio ad absurdum If any numbers were boring one of them would be smaller than all the other boring numbers, and therefore would be interesting simply for that. Therefore the smallest boring number is NOT boring: which is absurd. Therefore there are no boring positive integers. QED
@andrej6582
@andrej6582 3 года назад
Хорошо что язык математики и без переводчика понятен)
@user-de8nb8fn6s
@user-de8nb8fn6s Год назад
Постоянно этим восхищаюсь!
@ridefast0
@ridefast0 5 лет назад
Hi - I am probably wrong, but in your final answers you could start with (Z+2.pi.n) on the left hand side, so wouldn't it transfer across as -2.pi.n on the right hand side? I suppose it might depend on the odd and even symmetry of the sin() and cos() functions?
@NotBroihon
@NotBroihon 4 года назад
Yes, you are right notation wise. But it doesn't make any difference since n (and m) can be any integer (negative and positive). So the solution is still correct.
@ismaeljuniormoupe8881
@ismaeljuniormoupe8881 4 года назад
please the integral of e^cosx
@l3igl2eaper
@l3igl2eaper 5 лет назад
When are you going to teach Linear Algebra!?
@VKHSD
@VKHSD 10 месяцев назад
when he said "this guy" at around 5:00 he had the most perfect american accent
@omerhamzabilgin8963
@omerhamzabilgin8963 5 лет назад
Good video :)
@raphaelh6791
@raphaelh6791 Год назад
Can you juste right -iln(-1+V2) + n pi ?
@tristancam7219
@tristancam7219 5 лет назад
We have -1+sqrt(2) = 1/(1+sqrt(2)) therefore using the fact it is a quotient: -i*ln(-1+sqrt(2)) = (-i)*ln(1) - (-i)*ln(1+sqrt(2)) = i*ln(1+sqrt(2)). Can we now write down a shorter solution in only one expression ?
@bob53135
@bob53135 5 лет назад
I don't think so, but we could have found the second solution easily, as if z is a solution to sin(z)=v, then (π-z) is also a solution…
@user-qb5gw7tc9e
@user-qb5gw7tc9e 4 года назад
z = (-1)^n * i * ln(√2 + 1) + πn cases : n = 2m and n = 2m -1
@apotheosys1
@apotheosys1 4 года назад
Make a video showing that there is no z such that tan(z) = i
@blackpenredpen
@blackpenredpen 4 года назад
RealComplex Wait there isn’t?!
@blackpenredpen
@blackpenredpen 4 года назад
Wow very cool!!!! I just worked out. Thanks!!!
@vikasdeep6393
@vikasdeep6393 5 лет назад
Sir can you define log 0
@griffgruff1
@griffgruff1 3 года назад
Alternative solution: Let z = a+ib sin(a+ib) = sin(a).cosh(b)+cos(a).(i.sinh(b)) = i Equating real and imaginary parts gives a=0 and sinh(b)=1 So final answer is: a=0, b=0.88137
@EduardoHerrera-fr6bd
@EduardoHerrera-fr6bd 5 лет назад
Finally, bc is because!
@edrodriguez5116
@edrodriguez5116 5 лет назад
gotta do calc 2 again.
@blackpenredpen
@blackpenredpen 5 лет назад
Yup!
@borg972
@borg972 5 лет назад
I follow all the steps and everything's fine but I still can't understand how a function can be both periodic and unbounded at the same time. please help so I can make sense of this complex world..
@kevincastropalacios8585
@kevincastropalacios8585 5 лет назад
Saludos desde Perú!!!
@samharper5881
@samharper5881 5 лет назад
Please do a video about 1/(2+3/(4+5/(6+7/(8+9/(10+11/(12+...))
@afafsalem739
@afafsalem739 5 лет назад
Well well
@AhmedMahmoud-yj6yx
@AhmedMahmoud-yj6yx 5 лет назад
Find this limit with out using l'hobital's rule lim ln((x+sqrt(a^2+x^2)) /a) /x as x approches infinity
@AhmedMahmoud-yj6yx
@AhmedMahmoud-yj6yx 5 лет назад
I said without using l'hobital's rule because it is the easiest way i want it the hard way 😂😂
@fujoridev
@fujoridev 3 года назад
1:45 Ёкарный, я думал он по-русски сейчас зашпарит!
@CaradhrasAiguo49
@CaradhrasAiguo49 5 лет назад
10:09 Technically cannot do that (set arcsin(z) = ... + 2*pi*m) as it would no longer be a function
@JakeWaas
@JakeWaas 5 лет назад
tfw implied graph cut
@angelmendez-rivera351
@angelmendez-rivera351 5 лет назад
No, you can do that, just exactly in the same way you can write +/- when evaluating square roots. It is multi-valued function. If you want to be strict about it, the arcsin is a map from C to P(C), and the element of P(C) by which it is valued is unique, so it is a function.
@angelmendez-rivera351
@angelmendez-rivera351 5 лет назад
it's me It is a function. What you have failed to understand is that arcsin is not map from C to C, but rather a map from C to P(C). The output in P(C) is unique, though it is a set.
@GaryFerrao
@GaryFerrao 10 месяцев назад
8:00 know π is an integer. (quoted verbatim, but out of context 😂)
@sergiolucas38
@sergiolucas38 Год назад
The thanks for watching was good :)
@TheFinalRevelation1
@TheFinalRevelation1 5 лет назад
Is that a mic ?
@1976kanthi
@1976kanthi 3 года назад
No it’s a thermal detonator
@sebastiantabara2325
@sebastiantabara2325 3 года назад
When u did ln-1 shouldnt u have also put a plus 2pin so in the answer u should have at the end smth like 2pi(m+n)?
@sophiaabigai_l
@sophiaabigai_l Год назад
7:59 "you have to denote that pi is an integer" wait what
@AMAMohamedAurangaseep
@AMAMohamedAurangaseep 2 года назад
rpbp bro, nice lecture, Similarly, how to solve sin (i) = ??
@MrBeen992
@MrBeen992 4 года назад
So the sin inverse of a complex number is also multivalued ?
@darysparta9676
@darysparta9676 3 года назад
4:10 when she wants to be on top for once
@Shouray9891
@Shouray9891 4 года назад
How you write sinz =[ e^iz-e^(-iz) ] / 2i
@lenguyenvietcuong5379
@lenguyenvietcuong5379 Год назад
8:00 "π is an integer"
@mcmage5250
@mcmage5250 5 лет назад
I personally add 2 pi m instead of 2 pi n or 2npi
@mcmage5250
@mcmage5250 5 лет назад
Oh you mentioned him xd
@blackpenredpen
@blackpenredpen 5 лет назад
Yup! Alright, thanks for watching!
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