Formula for arithmetic series

[@vanzypubg8469]

Lol for years... throughout my entire University life, I'm even in my Masters degree now...and whenever I falter on my math, I always think "consult Sal"...bcz he never disappoints. Thank you Sir...thank you for the As

[@patcupo]

"Color changing is sometimes difficult." -Salman Khan

[@MasterTeeee]

But arithmetic series' aren't. He's a cool guy.

[@cybersaiyan9596]

laughs in Michael Jackson.

[@cancan7669]

Khan Academy is literally a life saviour

[@sethvlogs4387]

im having a mental breakdown because of mid terms

[@nerdtime1199]

twinnzeeezzz

[@menna7068]

Meee toooo

[@ojk3863]

lol u explain it all in the end but until then im like wtf how am i gonna remember it.

[@Mirsab]

0:54 mind blown, now I know why it's n-1

[@Voltron4ev4]

Best explanation on the net - thanks again Khan Academy

[@arrianmian7294]

Yeeeeah i got to 111th comment i am so proud of myself...but really the video explained way better then my teacher could in a week.

[@M4gicMark]

More subs than DramaAlert

[@noel2577]

at 6:20 you said that it makes intuitive sense because you're increasing by the same amount every time, i dont see how thats intuitive but would really like to know. can someone PLEASE elaborate on how it is intuitive? thanks in advance!

[@Debiprasad156]

I keenly watch your videos.It is very nice of you that you have uploaded the video on derivation of sum formula of AP.More than a million students appearing for their class 10 exams this march 2013 in india will remain greatful to you.Thanks

[@joyanntodd1341]

how do i find the sum of the next 18 terms and the sum of the first 18 term if im given an arithmetic progression ?

[@suryacreation05]

Thanks sir awesom...... from India

[@TheDrivenMind]

Same here, much easier to understand intuitively.

[@BSC-Square]

Great sir❤❤❤

[@rebekahhynson6602]

what is n? and how do you figure out what it is?

[@SnoozeTheRecluse]

How do you predict the (for example) the 15th term?

[@CheesyHotDogPuff]

a15 = a1(15-1)d

[@Healingson]

School is giving me grey hairs tbh

[@lusoo2005]

Same, my teacher says we have to watch this video, so im one foot in the grave.

[@endercatstudios2978]

AUUUUUUGGGGGGGGHHHHHHH! how am I going to remember this?!?!?

[@hanchengwu6062]

This explained it well. Thanks.

[@kgadimoney1526]

Omg thank you soo much I understand this now

[@soldierkhiyt530]

😂😩😩😩

[@TRADERSFRIEND]

Your brain is 3 times the size of the average human, thanks for simplifying things and helping me to muse my mind......

[@zahraashrafzade8948]

Thank you!

[@gustavlindell2753]

this was extremely helpful and understandable, thank you

[@sowbhagyanaidu7626]

Hello!!could any body explain the solution... If avijith saves rs.400 more each year than he did the year before and if he saves rs.2000 in the 1st year ,after how many years will his savings be more than rs.100000 altogether?

[@SaadAhmad007]

I honestly love you man! saved me at least 20 mins!

[@BSC-Square]

Love from India

[@crisgwyngieponferrada2039]

Very well said

[@horlacsd]

always learned this w/ the anecdote of a 10 yr old Gauss, finding the sum of 1-100.

[@ronitsen9432]

how to find the n in the 'n-1'

[@d0pamine599]

just count or identify the number of terms for example 3,7,11,15,19. your n will be 5

[@c-wayne-u]

Nice work. Thanks.

[@jaunceybotleng2619]

geat explanation

[@crazydude145]

Why n' th term is a+(n-1)d

[@georgeoota7397]

how can i got that for me

[@nikulbhati7733]

Thanks

[@picklerick5094]

what if they give me every figure except for the value of n. how do we find n?

[@aayushkucheria2644]

The value of n, plainly put is the no of figures given. Like from 2-11, the value of n is 10. If every figure is given, you can either count all of them, and that would be its value. OR You could divide the last term by the difference between any two terms (d), and the quotient you get is the value of n - 1. For example, let's take 1,3,5,7,9. The last term is 9 and the difference between each term is 2. Thus 9/2 is 4 with remainder 1. Add 1 to the quotient and you get the value of n. And in addition to that you also get your first element i.e. In this case 1, so you can cross check your answer.

[@padmashrivittal2799]

+Aayush Kucheria You are partially correct. The second method won't work if the series involves numbers lesser than 0 So taking the same example: if the series was -1,1,3,5,7,9..The number of terms is no longer 5

[@kawiahtunti]

you repeat your words so much

[@Zohirul-Jewel]

+K Serena It's to help you learn

[@TheDavidMetcalfe]

+Zohirul Islam Jewel Repetition does not help learning. It helps retention. One needs context and analogy for learning. Salman Khan is unfortunately rather weak in this area based on the tutorials.

[@Zohirul-Jewel]

***** Retaining new information is part of learning. You can look up context and analogy else where, this helps to learn the steps.

[@TheDavidMetcalfe]

+Zohirul Islam Jewel Retention has no value if one doesn't comprehend the instruction. This is where context and analogy come in. Because he's bad at tying his lessons into more basic knowledge that a student is likely to possess, comprehension suffers. This is where a lot of teachers fail miserably with their students.

[@Zohirul-Jewel]

+David Metcalfe You can learn context and analogy when you learn jobs where they use the math in, or you can just ask the math teacher at school where the would use the math they're learning in class, that's what I do. Sometimes the teacher will tell you that with out you even asking.

[@youssefa7172]

THANK YOU ALOOOOT

[@manaliliangelaeunice9259]

I am having my online class yet i still don't understand this argghhh i want academic freeze rn

[@iZainAli]

why we multiplyed n

[@MrMoeqt]

Because there are n terms in the sequence. So if we are adding up some term again and again, n times... it's the same as multiplying that 'some term' by n. It's kinda complicated to absorb at first but once you get it, you'll know exactly why with no problem

[@cloudmane4159]

I jusr need to know how to find the common difference omfg

[@zacfaustin7370]

@Khanacademy what does the n mean in (a+[n+1]d)?

[@prasadsawant4153]

Why did you do (n-1) ? Why not just 'n'. ?

[@dawarshakeel8203]

Bcz a,a+d,a+2d,a+3d+,...,+a+nd this is arithmetic series and for nth term if the formula would be tn=a+nd and u will gonna solve it let's say for n=2 a/c to the above formula t2=a+2d but in actual the 2nd term is a+d that's why we use tn=a+(n-1)d a/c to this t2 would exactly be a+d.

[@cabdimohamed2495]

u have not explained where is n coming from and you have to multiply it to the rest of the series

[@flower_girl4983]

I use don't understand ur version. My teacher give us an equation and we solved it. I he give us numbers to put in equation. Ur vensionnfrsio

[@gregoryyang8988]

Sometimes you repeat your words. (just saying)

[@kumarabhi123456]

5050 it is

[@nitkhuman6478]

eye Opener

[@avyaya123]

so im gonna fail maths

[@kanishmaray]

My teacher took a whole week to explain this 8 minute math to our class

[@humasaeed131]

this is sooooo confusing

[@lmaooo2548]

Stop making it complicated

[@shaniagrant9449]

unpopular opinion : I actually like comic sans

[@Elitea20]

Aerial for life

[@aryan-gg8sf]

This formula is too complicated not a good option lol

[@shankarvempati362]

We can't understand your hand writing

[@efath-bz8hv]

🤩🤩🙏

[@jaydeeeeb2786]

Yes!!!!!!

[@nicksu332]

god bless

[@ujbok8656]

mr khan, there's a problem in ur video.We can't watch anything. faltu

[@jenni4809]

what

[@living_in_spain_without_the_s]

😭

[@arrianmian7294]

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[@gimoosh4362]

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[@lbrtle]

Dingus khan

[@angelicabirata2214]

The heck

[@gimoosh4362]

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[@arrianmian7294]

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[@arrianmian7294]

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[@arrianmian7294]

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[@gimoosh4362]

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[@arrianmian7294]

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[@BarackBananas]

What the fuk is the d stands for?

[@tobywallace5614]

The difference between one term and the next

[@arrianmian7294]

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[@gpokriff2]

lol small world

[@aprilwithab7871]

wot

[@onii-chain]

bro this shit makes no sense u cant just use variables u need real numbers

[@nopparuj]

Thanks

[@arrianmian7294]

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[@arrianmian7294]

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[@arrianmian7294]

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[@arrianmian7294]

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