Introduction to arithmetic sequences | Sequences, series and induction | Precalculus | Khan Academy

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  • Опубликовано: 16 янв 2025

Комментарии • 434

  • @farvamo
    @farvamo 10 лет назад +827

    U explained me how to do it in 1 minute and my math teacher had 50 minutes and didn't teach me crap. THANK YOU

    • @dakotahippo9
      @dakotahippo9 10 лет назад +12

      OH MY GOD!!!! SAME

    • @CrisMadla
      @CrisMadla 10 лет назад +24

      Same teachers need to learn to teach lol

    • @farvamo
      @farvamo 10 лет назад +12

      Or atleast use these videos in class

    • @isaaca7372
      @isaaca7372 10 лет назад +5

      agreed

    • @upendersingh9980
      @upendersingh9980 5 лет назад +2

      l p I am sorry....

  • @user-hl6zs5jd4b
    @user-hl6zs5jd4b 7 лет назад +1400

    *pretends to understand*

    • @B1SQ1T
      @B1SQ1T 6 лет назад +52

      *actually understands*

    • @unexplained1396
      @unexplained1396 6 лет назад +38

      I have never related to something so much in my life

    • @ann1ka_p
      @ann1ka_p 4 года назад +35

      U know what they say 😂 fake it till ya make it

    • @trunchwood5908
      @trunchwood5908 4 года назад +8

      Am blank like seriously 😑

    • @jetski2322
      @jetski2322 4 года назад +9

      Dudeee sameee. I’m dumb.

  • @mayarae6272
    @mayarae6272 6 лет назад +61

    You are literally my math teacher. THANK YOU. In my math class we got 2 days to learn this AND piecewise functions, not to mention the fact that our paid teacher has no clue what she's doing. Honestly, thank you, you're the only reason I'm not failing at this point.

  • @cheezytm478
    @cheezytm478 5 лет назад +224

    Me: hey, what’s the speed limit? I can’t see from here.
    Friend: oh yeah, it’s an=a1-d(n-1)

  • @bloodykills7509
    @bloodykills7509 8 лет назад +854

    *QUIT READING THE COMMENTS AND GO BACK TO STUDYING.*

  • @Anonland
    @Anonland 7 лет назад +517

    This is a useful math skill necessary in everyday life.

    • @pokaay3163
      @pokaay3163 5 лет назад +61

      funni jok

    • @graceykb6392
      @graceykb6392 5 лет назад +35

      Ok boomer

    • @trevorking7461
      @trevorking7461 5 лет назад +14

      R/woooosh

    • @JoJo-sb8gr
      @JoJo-sb8gr 4 года назад +7

      Cap

    • @tempdraw5428
      @tempdraw5428 4 года назад +10

      Never knew 🤣ok suree I thought this was olny used when your a mechanic but yes this was very helpful. 😊✌👍

  • @Matthew-McCallister
    @Matthew-McCallister 4 года назад +72

    Currently trying to teach myself Calculus II as my campus has shut down for the remainder of the semester and classes are online. I am a math major so now I have to teach myself calc based physics, Statistics, and Calculus all at the same time from home. This helped so much. Thank you!

    • @princelazaro4943
      @princelazaro4943 Год назад

      and your point is? your kid is getting introduced to arithmetic progression, series is a lot more, it leads to the discovery of calculus and limits@Exoticanimalslover

    • @ravikiran4495
      @ravikiran4495 Год назад

      @Exoticanimalslover cus you're just that dense Sorry to say

    • @haaannnooo
      @haaannnooo Год назад

      @Exoticanimalslover haha im in 9th grade and currently learning this too 😅

    • @UncensoredSigma
      @UncensoredSigma Год назад

      i'm in seventh grade and i'm learning this

  • @onelson138
    @onelson138 7 лет назад +353

    I HATE ALGEBRA WITH A BURNING PASSION

  • @chillwatermelon7780
    @chillwatermelon7780 5 лет назад +73

    My math teacher said if I didn't know this after him writing it out then I was challenged. You just explained it and I understand. Who's big brain now?

  • @antonnchindo6006
    @antonnchindo6006 9 лет назад +169

    I never listen in the math class RUclips math tutorials explain my work in 10 min ain't got time for 2 hour lectures

  • @hazielllanes973
    @hazielllanes973 6 лет назад +123

    So in conclusion u have confused me more

  • @simon333_
    @simon333_ 6 лет назад +75

    Its almost 4am and I have my precalc exam tomorrow...

  • @shanalaus
    @shanalaus 4 года назад +24

    When you want to learn then your internet suddenly turns off: *i just lost my motivation to study*

  • @aileen_0714
    @aileen_0714 Год назад +6

    That made so much sense, my teacher took like a week to explain you took just 4 minutes of explanation and now I get it THANK you I have a test on this today I had to see it😭

  • @chadedgeworth9369
    @chadedgeworth9369 7 лет назад +34

    What would we do without Kahn Academy

    • @shatter3374
      @shatter3374 4 года назад +4

      @Alan Guchemand facts like when am i gonna use this!?!?!?! in life

    • @anon8197
      @anon8197 3 года назад +3

      @@shatter3374 pretty sure society wouldn’t be as advanced as it is if students weren’t forced to learn this, but who knows.

  • @Miss_Yuriko
    @Miss_Yuriko 4 года назад +5

    dude. ty so much. I couldn't comprehend anything during class today and I suddenly feel like an arithmetic sequence god now that Khan academy explained it.

  • @krutomjer
    @krutomjer 12 лет назад +11

    Congrats, your accomplishment will be eternally celebrated

  • @edwinniemandt1995
    @edwinniemandt1995 6 лет назад +25

    WOW THIS IS GOING TO HELP ME IN THE EVERYDAY WORLD. 👍👌

    • @thecornseller
      @thecornseller 4 года назад +3

      nice one bro

    • @nakamurasupermario64miyamo61
      @nakamurasupermario64miyamo61 3 года назад +4

      I thought exactly like this in high school, now I have an anime profile picture and I'm making $13 an hour at a dead end job trying to re-learn math to go back to school.

    • @Whatyulookinat
      @Whatyulookinat 2 года назад

      @@nakamurasupermario64miyamo61 hi… what happened ? U returned to school?

    • @nakamurasupermario64miyamo61
      @nakamurasupermario64miyamo61 2 года назад +1

      @@Whatyulookinat I recently got a raise to $25/hr at the same "dead end job" I was referring to. Getting good at math was a big part of that though because it kept my mind sharp and able to sort out complicated situations in a very efficient way. I'm still studying math because it's difficult and not having a mountain to climb is boring and depressing.

    • @nayshaprasad8318
      @nayshaprasad8318 Год назад

      depends on the job you take???

  • @tripppurviance2083
    @tripppurviance2083 9 лет назад +53

    Where do I donate? My 14 year old and his mother were at their wits' end last night trying to figure this out in a common core math book. Watched this 7 minute video, did homework, went to bed. THANK YOU!!!!

    • @pigeonlove
      @pigeonlove 5 лет назад

      Wow you have Google to find the video and you don't have Google to find out how to donate...

    • @views-dz7cg
      @views-dz7cg 5 лет назад +2

      @@pigeonlove Google is a multi-billion dollar corporation that profits off selling the data of all of their users for advertisements. How much money have they already made off of you?

    • @fushiie9583
      @fushiie9583 5 лет назад +1

      @@views-dz7cg and yet here you are...commenting on a google account.

    • @ericawu8779
      @ericawu8779 4 года назад +2

      @@pigeonlove maybe she does know how to donate, she's just sayin' she gonna donate cuz this hella useful
      Edit: and sometimes google's doesn't find you everything
      Edit: oh ya, lastly, she might've gotten this from khan academy or youtube NOT google
      lmao

    • @boniquer931
      @boniquer931 3 года назад

      lucky ur 21 now and u finished from school

  • @digo901
    @digo901 6 лет назад +12

    Thanks from Brazil. You're helping with math and with my listening in English! :D

    • @lucasants4872
      @lucasants4872 5 лет назад +3

      I too XD. I am 13 years old and I have been only watching videos in english and reading english books in PDF to practice my english.

    • @user-fh2rw9zh8g
      @user-fh2rw9zh8g Год назад

      ​@@lucasants4872hello there, you're now 16 years old. I hope you keep up this mindset

  • @ericawu8779
    @ericawu8779 4 года назад +23

    "arithmetic"
    who else pronounces it differently?

  • @asselann9870
    @asselann9870 3 года назад +13

    You can also write d= a2-a1 , to find the common difference. 💖

  • @aki-kf4bo
    @aki-kf4bo 5 лет назад +5

    Woah this taught me so much

  • @vaishnavchandra5220
    @vaishnavchandra5220 3 года назад +4

    Thank you so much. U hv'e no idea how many lives u have saved

  • @user-lt8vl4tr8p
    @user-lt8vl4tr8p 8 лет назад +230

    GOD, I HATE MATH!

    • @calicowav
      @calicowav 8 лет назад +23

      HATE, I GOD MATH

    • @xaviersson7047
      @xaviersson7047 8 лет назад +12

      I, MATH GOD HATE!

    • @manjotpadda
      @manjotpadda 8 лет назад +9

      I,GOD HATE MATH!

    • @benyosef6570
      @benyosef6570 7 лет назад +8

      GOD, MATH I HATE

    • @allentowncola937
      @allentowncola937 7 лет назад +8

      Palmtop Tiger thats impossible.You just hate the uncomfortable feeling of not being able to understand it.

  • @jijgmfamily3210
    @jijgmfamily3210 7 лет назад +103

    this is so confusing wtf is n

    • @kingviper5700
      @kingviper5700 6 лет назад +4

      the index

    • @TortureBot
      @TortureBot 6 лет назад +16

      I thought I understood number sequences, and then I watched this video.

    • @hazielllanes973
      @hazielllanes973 6 лет назад +1

      Kingviper what’s that

    • @kingviper5700
      @kingviper5700 6 лет назад +4

      @@hazielllanes973 it depends really, it can be the power (how many times you multiply), or an arithmetic progression (continuous increase of values where the difference is constant) and multiply from those numbers. I think, I've forgotten about this video, so it might not be related, what I've just said

    • @hazielllanes973
      @hazielllanes973 6 лет назад

      Kingviper thanks

  • @katzbeanz
    @katzbeanz 9 лет назад +8

    this helped, me with my math homework,

  • @charmingcurls7401
    @charmingcurls7401 Год назад +1

    When my teacher is explaining this in school, i don't understand a thing. But somehow this guy on the internet explains it in 7 minutes! Thank you so much!

  • @reptilelover2129
    @reptilelover2129 4 года назад +6

    Different math types are specific to each job. So to the people who are asking "WHEN AM I GONNA USE THIS!?!?" It honestly depends where you work.

    • @nakamurasupermario64miyamo61
      @nakamurasupermario64miyamo61 3 года назад

      I said the same thing during my math classes in high school and looking back, that's probably one of the worst mindsets I ever had. I graduated not knowing what I really wanted to do. Now I'm 23 and want to be an engineer and I have to relearn everything if I wanna go back to school.

    • @nakamurasupermario64miyamo61
      @nakamurasupermario64miyamo61 3 года назад

      @Lil smackaroo Yeah, go for it and aim high. After high school it's easy to hop into an entry level job "temporarily" and before you even have time to realize it, you're 23 and watching everyone you went to high school with graduating college and getting their dream jobs. Fortunately that slapped me in the face while I'm still young and have at least 42 years of career left.

  • @wardielaw7856
    @wardielaw7856 2 года назад +8

    Literally understood this in like 30 seconds after you explained it but my math teacher couldn’t in a 70 minute lesson

  • @tr4629
    @tr4629 6 лет назад +4

    this saved me when i wasn't getting the difference between the concepts at all

  • @jaydenchesslife
    @jaydenchesslife 4 года назад +2

    Intresting! Great video Sal!

  • @bobfredjeojrsrthe3rd490
    @bobfredjeojrsrthe3rd490 3 года назад +4

    Thx man you helped me more in the first 2 minutes than my teacher did in 50

  • @bobademon9332
    @bobademon9332 3 года назад +4

    *Sweats and pretends to understand while mom glares at me*

  • @Aristothink
    @Aristothink 11 месяцев назад +1

    I love math sequences and specially Khan Academy. Great video !

  • @Aristothink
    @Aristothink 10 месяцев назад +1

    Arithmetic Sequences are amazing. It's a good exercise to massage to reinforce math in our brains. Great video. Khan is wonderful to help our students 🙂

  • @clownsRscary1
    @clownsRscary1 7 лет назад +29

    as i watch both rick and morty and the big ban theory i understand all of this,

  • @muhammed-amiinmuhamud5387
    @muhammed-amiinmuhamud5387 7 лет назад +24

    im freaking out

  • @lovelydovey7778
    @lovelydovey7778 6 лет назад +4

    Thank you for this video I understand it now thanks again!

  • @dbzfan655
    @dbzfan655 6 лет назад +10

    I remember this in High School. It was pretty straightforward. Thank you for the video.

  • @instertname4893
    @instertname4893 2 года назад +1

    Thanks there’s a test about this tomorrow and this helped

  • @madilynharris5969
    @madilynharris5969 4 года назад +7

    When I understand this in 4 mins and my math teacher couldn’t explain it well in a 1hr and 45 min class

  • @mrdxb1154
    @mrdxb1154 5 лет назад +10

    Easier way : check how many it adds up every time then turn it from positive to negative or negative to positive then the first term minus the change negatively for example -5 -3 -1 5n-7

    • @melvinramos2849
      @melvinramos2849 5 лет назад +3

      MrDXB wait what? I’m confused

    • @shak273
      @shak273 3 года назад

      Me who still doesn’t understand:

    • @lessthanpinochet
      @lessthanpinochet 2 года назад

      The way he explained it was just fine and will resonate with more people.

  • @abdallahraafat432
    @abdallahraafat432 8 лет назад +9

    PLEASE USE A SLIGHTLY BRIGHTER COLOR THAN SOLID BLACK!

  • @myronmteul7613
    @myronmteul7613 3 года назад +1

    Omg thank u so much it really helped allot 😭

  • @saadabilmona4389
    @saadabilmona4389 5 лет назад +2

    Arithmetic sequences can be a set of succeeding numbers that are decreasing. The common difference can be a negative number

  • @zx6r502
    @zx6r502 5 лет назад +7

    I already know this why am I watching this

  • @yuphengvang3895
    @yuphengvang3895 9 лет назад +2

    Thank you so much for this video!!! Now I know how to solve this! Your the best

  • @ickyngo1025
    @ickyngo1025 5 лет назад +1

    This is helpful !!❤

  • @anirudhmenon5281
    @anirudhmenon5281 9 лет назад +2

    thank you Mr.Khan

  • @hypervenom5960
    @hypervenom5960 3 года назад +1

    Well ACT exam in 4 hours and now I’ve can cross this off a long list of rules I need to revise.

  • @maxsotelo1089
    @maxsotelo1089 8 лет назад +3

    Very helpful :D

  • @JohnTeller-y4k
    @JohnTeller-y4k 4 месяца назад +1

    Thanks for the video

  • @ryanfrizzell736
    @ryanfrizzell736 2 года назад +1

    Arithmetic sequences = hallmark of life

  • @dognibbler
    @dognibbler 4 года назад +4

    imagine having all your subs being teachers

  • @rskenny4446
    @rskenny4446 5 лет назад +1

    Thanks I need to pass my test

  • @Joci555
    @Joci555 5 лет назад +4

    Idk if this helped me or made me more confused butttt thank you 🙏🏽

    • @uncle_.
      @uncle_. 2 года назад

      Lmao that's all of sal's videos

  • @Tump3039
    @Tump3039 Год назад +1

    Great Video

  • @pokaay3163
    @pokaay3163 5 лет назад +7

    anyone else studying before their finals say I

  • @shawnjung6799
    @shawnjung6799 6 месяцев назад +1

    TYSM

  • @jennabaily2282
    @jennabaily2282 5 лет назад +3

    😔guys I need your prayers, I got my eoc tomorrow.

    • @lemonlime07
      @lemonlime07 5 лет назад +1

      Jenna Baily how did it go?

    • @jennabaily2282
      @jennabaily2282 5 лет назад +1

      Suhani Rampuria it went well and I passed.

    • @lemonlime07
      @lemonlime07 5 лет назад +1

      Jenna Baily congratulations 😀

    • @jennabaily2282
      @jennabaily2282 5 лет назад +1

      Suhani Rampuria thanks.

  • @carlylexa6113
    @carlylexa6113 4 года назад +8

    I am literally sitting in bed sobbing trying to understand this. please tell me I am not alone I can't take school anymore

    • @78anurag
      @78anurag 3 года назад +1

      It'd ez to understand lol

  • @shaqiloneal2605
    @shaqiloneal2605 7 лет назад +3

    what indicates K and d(n-1)

  • @lorrainegibbons2468
    @lorrainegibbons2468 6 лет назад

    Satisfying 😣✅✅✅🔥🔥

  • @KingCadmos
    @KingCadmos 12 лет назад +7

    I can.

  • @tedchoi8488
    @tedchoi8488 7 лет назад +2

    I know that this is not a arithmetic sequence, but what should I say with the common difference of numbers of range in quadratic such as 1,4,9,16,25,...?

  • @augustusprime0_o
    @augustusprime0_o 3 года назад +2

    You explained this so well 😭

  • @angel-hh1wz
    @angel-hh1wz 4 года назад +3

    what does the (n-1) mean?
    _please help me_

    • @ryanpowers8973
      @ryanpowers8973 4 года назад

      *my exact question like where does that 1 even come from AHHHHH*

    • @angel-hh1wz
      @angel-hh1wz 4 года назад +2

      @@ryanpowers8973 i think i understand it now, the -1 (in n-1) represents the "previous term"

    • @ryanpowers8973
      @ryanpowers8973 4 года назад +1

      angelxxxc ahh that makes a lot more sense. Thank you!

    • @78anurag
      @78anurag 3 года назад

      @@angel-hh1wz Yes you got it!

  • @wasimgill4101
    @wasimgill4101 4 года назад

    Khan Academy, u do wonderful work, but can background of videos become lighter color like white or grey?

  • @garretta5804
    @garretta5804 7 месяцев назад +1

    Is defining an arithmetic sequence how you answer it? also what does the (n-1) mean? what is its purpose??

  • @omegasteve8485
    @omegasteve8485 Год назад +2

    …. I did not understand a single thing you said goodbye im going to the organic chemistry tutor

  • @pixelfish3395
    @pixelfish3395 4 года назад +1

    How did I sit through and hour of my teacher trying to teach this and walking out with less understanding of math than before I walked in, but come here and know how to do math in ten minutes?

  • @cindycharestugaycutie2848
    @cindycharestugaycutie2848 2 года назад +1

    Good morning, I just want to ask permission to use this video for my class discussion purposes only.
    Thank you!

  • @honeyandlavender_
    @honeyandlavender_ 4 года назад +2

    Why do I need this for Psychology, again?

  • @thepianist123
    @thepianist123 4 года назад +1

    You have explained with some kind of notation here. Where the lower limit is n=1 and upper limit is infinity. My question is what is that notation? Where can I know more about it?

  • @chanakyaneeti8016
    @chanakyaneeti8016 4 года назад +1

    Nice video

  • @ekatajaceperinda813
    @ekatajaceperinda813 7 лет назад

    Thank you!

  • @princesspeachgaming4162
    @princesspeachgaming4162 6 лет назад +6

    i can't wrap my head around why you use n-1

    • @nazarm6215
      @nazarm6215 5 лет назад +1

      It's simple. Plugin in 1 and subtract one and you'll get the value for a of 1, to get a of 2 you need to subtract one, otherwise it will give you the 3rd term

    • @HeavenlySunset24
      @HeavenlySunset24 5 лет назад +2

      @@nazarm6215 This makes no sense

    • @teetsieroll4529
      @teetsieroll4529 5 лет назад +1

      Nazar Maksymchuk ohhh thank u so much

    • @78anurag
      @78anurag 3 года назад +1

      Because the first pattern for example adds the previous number of a number in the set with 2. So a number in that set is equal to the preceding number +2 (Just look at the pattern, it follows that way, the pattern itself means that adding to a number in that set gives you the next number, meaning that (a number in that set)+2= next number. Ultimately leading to that the number which we added 2 to is the predecessor of the next number since the operation of adding by 2 gives us the next number). We are going to assume the position of a number in the set as n. The predecessor of that number will be at position (n-1) (since the predecessor is one position behind) .
      From my opening sentence we can write a number as the sum of the predecessor and 2 I.e (n-1)+2. (I'm just repeating this again)
      So we get,
      For a number z with position in n in the set its value is going to be it's predecessor number+2= An-1 +2
      z= An-1 + 2
      A is just a notation for any number so we can replace z with A.
      A= An-1 +2
      Where n is the position of place the number is located is in the set.
      Simple as that.

  • @TheVincentVanGogh
    @TheVincentVanGogh 4 года назад

    Look where this Quarantine led me too..

  • @Kcgramerrr
    @Kcgramerrr 6 лет назад +4

    Is this actually PreCalc? I'm learning this in algebra 1

  • @kevh.2652
    @kevh.2652 6 лет назад +1

    isn't (n-1) supposed to be an exponent to 2 instead of alongside it?

  • @abbyadamo2155
    @abbyadamo2155 6 лет назад +1

    Emma do your work and stop scrolling through the comments

  • @usuaan
    @usuaan 5 лет назад +2

    lol I have a test on this today wish me luck

  • @notteam6560
    @notteam6560 2 года назад

    I love you thank you

  • @yaaaserrr
    @yaaaserrr 11 лет назад

    Thank you :)

  • @seongsik
    @seongsik 6 лет назад +1

    yeah, but how did he write it with the n=1 to infinity thing

  • @downtownpets
    @downtownpets 12 лет назад +1

    Are you familiar with who the videos are for?

  • @amyhilling3094
    @amyhilling3094 10 лет назад +2

    What programme do you use when writing

  • @siennacoventry33
    @siennacoventry33 4 года назад +1

    Why is it n - 1 on the first questions??

  • @selahstrain1010
    @selahstrain1010 6 лет назад

    in the a'n' or a'1' what does the 'n' and '1' mean ?

  • @elkhouryeliza9715
    @elkhouryeliza9715 4 года назад +1

    How can we determine the next term of an arithmetic sequence?
    A can someone please answer me I'm so confused...

  • @santoshkothekar8558
    @santoshkothekar8558 6 лет назад +1

    Nise sir

  • @julijoba9002
    @julijoba9002 3 года назад +1

    i have eoc testing in a week, im speedrunning studying when I've never studied...

  • @stuffguy7796
    @stuffguy7796 4 года назад +1

    Mans handwriting bout to make me act up

  • @lu-zn4dq
    @lu-zn4dq Месяц назад +1

    I am still failing maths

  • @chris.s6768
    @chris.s6768 Год назад +1

    I thought you were supposed to use Un and Usub 1 U sub 2 etc for your nth terms… im confused why are you using k and a, I thought a represents the first term or is this different the american way?

  • @wisdom561
    @wisdom561 4 года назад

    All these people trying to study. . . . and then there's me who just saw this vid at 1 am, but don't wanna sleep so watches anyways

  • @poopty5150
    @poopty5150 3 года назад

    6:33

  • @gohanwanabe
    @gohanwanabe 8 лет назад +1

    How did he get (n-1)

    • @christelcardenas
      @christelcardenas 8 лет назад

      gohan wanabe i know this is late, but "n" is apart of the formula. It represents the number in the sequence you're looking for

    • @78anurag
      @78anurag 3 года назад

      Is it too late now?

    • @gohanwanabe
      @gohanwanabe 3 года назад +1

      @@78anurag I don’t know

  • @WWJDinAlaska
    @WWJDinAlaska 4 года назад +2

    I dont know if I'm more confused or not. I'm stressing out, I am failing school. Also told my teacher I would do my homework and I have a meeting with her first thing in the morning. But it's 1:30am and I don't understand still. I'm so bad at math and school. My teachers at school are not good at their jobs either.😨 also why is letters aloud in math.