Introduction to functions

[dmanno3]

i was thinking THIS IS ACTUALLY helpful! and that 9 mins HAS gone by quick!, untill i seen that pedophile at the end of the video i was like... :(

[someone20ify]

i saw his chemistry videos and bilogy videos,i have to say that he is very at them but he is very bad at teaching maths and my teacher teaches better!!!!

[egglesxx]

Why can't all math teachers be this entertaining? D:

[applerox101]

your teaching style is awesome and all.....but i feel dumb lol i still dont get it!

[MiiSha1991]

i lub u dudeee

[liv4h]

Sal, beside explaining math in a simple way, you entertain me as well.. so I do both at the same time. Let me say.. thanks :) Keep up the good work. God bless ya.

[dgovern]

do you think people in middle school 8th grade should learn this?

[toddmfay]

You just summed up exactly how I felt about functions my entire algebraic life in the first 15 seconds of this video. I feel so much better already. You are so relatable (pun intended).

[Cletzenbougen]

I love you Sal. Math savior.

[meerzadayama]

I just found how functions work! Thanks for your help Sal! Love and Respects for you! Cheerzzzz

[howard7731]

superstitious....? Thanks for all your help Sal cheers for the vids

[deefilms1]

he is such a great math guy!!!!

[MJFslovak]

This video is pretty funny 

[TheFakeDeathHD]

dude, your so awesome!

You should get a price or something for your work!

Thumps up so he can see!

[htcjunkie16]

@TheFakeDeathHD A price? Sigh -_-

PRIZE!

[summercures2]

Food(Sal)= crap

Sal(crap)= toilet flush

crap(toilet flush)= return to computer

Computer(Sal)= more math videos

Math videos(student)= A's on tests

= )

[gonchienelmundo]

sal ROCKS

[Infowarriorification]

you are 10x better at explaining stuff than my math teacher

[SirJakeRogers]

@Infowarriorification Well at least they try, be grateful.

[ryno123321]

Sal would produce ATP :3

[qcr1996]

Haha. Poison+Sal= No math videos= No A's on exam .

[BestCoolGuy22]

What about functions that are written as y = something instead of f(x) = something?

[Stupidjuice817]

Bahahahaha. You're awesome.

[VegitoBlitz24]

Yo dawg, we heard u like functions so we put a function in yo function so u can derive while u derive.

[jesterkid88]

any one that clicked dislike must of got an "F" on their math test

[DarkstarJFL]

Khan Academy/Sal>School/Teachers

[abrahm714]

me(math videos)=realization of my stupidity 

[browno26]

@abrahm714 you(you(math videos)) = you (realization of your stupidity) = you(demonstration of understanding the video) = irony

[MrYou2berz]

thanks, you teach better than my two math teachers combined!

[PadawanLara]

awesome man. I watch these on my math teachers site.  check out markrogers0960

[2Vproductions]

Good job with the videos, very helpful and not complicated

[erikkle]

Very good and educating video! Great for me who's doing distance schooling :P!

[swe3tl0ve]

I have a math test today! =( lets hope I get an A!! bc this is one I didn't understand in class

[mariahphilmrazem]

wow i loved this. it clarified and you were hilarious. you remind me so much of my math genius friend who has the exact same sense of humor haha. keep making videos. you make a great teacher!

[KailowKrow]

4:28 will make math videos for food

[lust666lust]

ajajajajajajaja Sal Khan you are the best profesor ever! <3

[xat32]

jeje ur funny XD

[444zane3]

1:53 exactly what i was thinking. except without the big word that i dont know what it means

[Rensyl]

your videos are really helpful thank you.

It could be better with better quality but it's ok anyways.

Greetings from argentina.

[789123Y]

Brings back some memories from school when there were acctually pictures of "function machines" in our books.

[DarklightALBANIA]

The way you said death ,like that would really happen in the near future by Poison,ROFL.

[ragethefail56]

okay all i got on my mw is a bunch of ordered pairs and a small graph. how do i relate this to my hw? the title is different repersentations of functions...

[homesickgirl4]

@ragethefail56 just graph the xs and the ys after you solve them -.-

[zamrock20]

I love your teaching style man. Entertaining and informative, those 9 mins passed without me even noticing :)

[kenasiagir]

sal is funny

[DirectedByNate]

The first time I saw f(something) it was on a standardized test. I thought F was a variable and I tried to solve for it....

[Arsh7777777]

@steelplushie15 yeee the snake works!

PS -- Sal, great video my man. You rock btw! Did I say that for the thousandth time yet? NOOOOOOOO!!! That's ridiculous...i'm almost there though ;D

[Arsh7777777]

@steelplushie15 No thumbs up...if only you hadn't asked for 'em!!!

[cenasucks4eva]

damn i hate when people make math look so easy!! thanks for the video man, very clear and it helped a lot

[JiMmOo0]

IN WHAT GRADE DO YOU GUYS TAKE THIS ?

[fridayinlovely]

this was actually really good!!! thank you!!!!!

[blacklightning98]

:3 thnx

[haloidiot]

"Sal(Poison)=...Ugh..DEATH. No..no no no, i'm not going to say that" *scratching the "poison" off* LOL

[rice9195]

Made me more confused, no help at all, how is talking about food gonna help me get an A, sure now I know why I would use functions but that doesn't help me finish the questions on my homework!!

[MrMcannon]

@rice9195 cause ur dumb

[M000tube]

oh wow, incredibly simple, thanks

[yardapeJV]

Good video, but I take exception to you being a function. If food gets put into you, there are many, many outputs, videos being only one. But it is fundamental that a function assigns exactly ONE output to every input, so your example is false, and also misleading. You have many functions that describe you and define you, but you yourself are not a function. For example, there's a Sal temperature function, which is if I put an exact time into the box, I get out your temperature at that time.

[Kiralay0]

Sal, I love you! Thanks for explaining everything in such a clear, easily understandable, close, and funny way.

[Lindzey1702]

I love this guy!

[uubboy14]

@Lindzey1702 you stupid ducaduc bunk

[BlitzddsBen]

god damn i still dont get it.

[Vorbis5]

god sent this man to me. i am infinitely grateful.

[missbiss101]

I have to watch this vid and two more for homework..and i am in 7th grade...haha and it actually makes sense to me...

[Mundine1406]

OMGGGGG f(x)= love uuu many thanks !!

ur really gooddd at this!!

[fashanu1000]

feeling the same thing i dont understand the real world application to functions the idea doesn't make sense btw this comment is 20 seconds into the video

[manageo]

My name is Keefe

[uubboy14]

@manageo dont nobody care waht yo name is lol

[TheAwels]

cool, one



[Einaikou69]

Stephen Hawking(Sal(Math Videos))= SMARTEST MAN ALIVE. You make the toughest equations answered by 7th Graders. Thanks! Go Khan!

[DREADTHORN]

Who the hell failed after watching this guys videos?

[omgitsshivi]

I am really curious about what sal looks like

[daniel10alien]

@omgitsshivi its called google images......

[draknadraik]

Haha bloody funny!

[MrSultan13]

THANK YOU, my teacher is a polish guy with a thick accent and I can't understand what he says. Thank you khanacademy :D

[ophsj]

This is actually really awesome... I'm working on algebra in college. I'm pretty good with math but haven't grasped functions yet. I've been stuck on chapter 4 til really recently. After watching this video, it all makes sense! Thanks

[3200manpro]

Hahahaha I love khan academy so much!

[pufifa]

I LOVE YOU!

[superstarpheonix]

"videos from khan" input ,when they go inside us .......our teachers say " amazing output"

[musiclover73408]

like this guys teaching style I get it now

[mayhoo22]

sal(food) = steaming turd

[eltranced]

understood it @ 2min

[bolmung]

Lol. This guy's like Omer(from MMOhut.com) but with math videos xD

[iWriteUinMyDeathNote]

lol nonono not death

[akshaysoniboss]

hi this is akshay "sal" . u r just brilliant. i like your presentations very much

[ezshi87]

thx so much dude. im studying math for my DATs and i didnt do this math in 6 years. its a huge help!!!

[andreasggeorgiou000]

Sal?? Ur the MAN!!!!!!!!!!!!!!!!!!!!!

[Kataang4evr96]

I love these videos so much. I had no idea there was an even/odd rule for functions; my other curriculum never mentioned that!

Thanks so much, Sal!

[Alongcamelucy]

THANK YOU SO MUCH! X

[hzzic]

Sal is a genius!

[spandaize]

Khan u r a genius!!!!!!!!!!!!!!!!!

[spandaize]

Khan u r a genius!

[jenbuku]

me(sal's videos)= laughter and education

[annetsak]

You are my hero.

[beamer002]

This is going to help me on my math project so much!!

[shackun1]

these comments plus the video fells like school at Home! nice man thanks think imma do good in math tomorow

[randompeeps999]

HAHAHA!! this is hilarious!!!! wowits funny AND helpful!!!!

thanks sal!!!!!!

[YesukaB]

me(math videos)=good grades and happy

[Splinta141]

khan + 2joints + the internet = khan academy

[Carlhockey1]

hahaha this guy is hilarious+ hes a genious + he should be my math teacher = SUBSCRIBED

[Carlhockey1]

hahaha this guy is hilarious!

[tonga4lyfe1]

Bro thank you Sal, because of you i am not going to drop out of school, ur a blessing to youtube and the world

[MrAndydudeta]

The answer is poop, Saul. Saul(food)=poop.

[kentokae]

@MrAndydudeta LOL and you input Sal's Output! for A's in math! If you input Poison, then Sal would output "the Runs" You'll streams A+s like running water!

[Kappa1000]

I'm Pedro and you're fantastic! =D

[MattSniper117]

im like thinking functions are cause and effect

[pumkinkingjack1]

you are my hero...!

[paulceltics]

7:35

[paulceltics]

You are my best friend, seriously. lets hang out sometime

f(hangover)= me+Sal(win)

[rissha242]

I AM NOT GOING TO FAIL MATHS ANYMOREEE!! OMG THANKKKSSS!

[NeediSleep]

Sal(math videos) = more knoledge + me

me(more knoledge) = a+ on test + sal

Me(sal(math videos)) = 4.11 gpa. < - My output.

[NeediSleep]

FOOD f(x) = POOP :)

[fadddy2]

6 (dislikes)=Fail

[remuslupinhp]

function video(sal) = super funny...lol:D

[LoveDashayeee]

Do Any Body Get This?

[FireBenderKwyna]

I wish you taught my class. Our maths teacher is an idiot.

[ZombieNozz]

This is awesome. You have the ability to just switch lights on in my head. You rock, I appreciate your help with passing my class. :)

[supabeast23]

Thank you so much!!!! SAL IS AWESOME!!!!!

[toolbass24]

Sal, ur my best friend

[MixesAndStuff]

Hey Sal, good people tend to get assassinated (John Lennon, J.F.K., Ghandi, etc.) Try not to get killed, that would suck.

[wazed8]

Sal, watch out for teens and adults against the spread of education!

[nintendo768]

sal(food)=crap

[mb69ful]

o ok at first i was going to send sal food and a new pc but sal just needs food so would sal like a muffin XD

ps nice video :)

[tikitorch143]

I officially love you!!! It make it so much easier.. I was also wondering WHY I even needed to do functions, since I can do substitutions in my head...

This will make the rest of my school year so much easier...

Makes me mad that my 8th grade teacher (not in that school anymore) told me that math should be learned by memorizing definitions.....

[acconliffe]

sal u fucking rock! keep doing what u do!

[koolkitty9876]

Oh my gosh, Sal, I've been watching your vids, and I'm learning a LOT, and I clicked this and I remember learning it in Algebra around 2 years ago...it was confusing, but I can't believe you used the BOX! :D

[laurisvillegas]

omg, thank u so much, I love it, Im pretty sure I'll give u food soon

[tambolerzzz]

Be Blessed, sal. &hearts;

[ZipperHead31]

Nobody wants math videos on YouTube...

[laurisvillegas]

@ZipperHead31 Actually I nedded

[davidgo24]

Love you Sal!

[heygurlhey231]

i was totally screwed before i saw this..

thanks!(:

[sgt7]

i thought the sal/food function was quite helpful. It added a dimension i could relate too. thanks.

[Andruto23]

so relieved wen i found outdat khan did functions n im gonna ace me math exam :)

[autumnreign86]

lol @ sal of poision that was funny

[jordananderinful]

that was a super helpful video. i need a little explanation about analyzing functions.

[EternalDestiny95]

sal(food)=videos..

LOL

[gamemaster014]

Sal(poison)=no more math videos

You(no more math videos)= F on math tests

[toasty9989]

Sal(food)=Poo lol

[nishan29]

give him food to math...great deal

[pkrind]

Very good video sir I like it very much thanks for such a nice work

[Gnaw321]

you cann't spell functions without fun :))))

[theOman333]

loooooo.. u get the idea.. there wouldn't be math videos.. haha

[underglow60]

4 dislike=4 low paid teachers

[LatinBood]

my high school is hiring dude teach me math!! make it fun

[jinx1441]

LOVE IT!!! Wait, I have a function: Sal(YouTube)= Millions of happy people. TA-DA~!!!

[avi823]

give him food!!!

[kristingem1]

THANK u soooo much!!! Bless u:)

[LucyRockprincess]

omg ur analogy is hilarious

[Ngelcanfly]

lol funny

[BigDaddyBee1000]

sal(poison)= me(failed gr. 11)

[mohabbat66]

@BigDaddyBee1000

in that case poison me too i failed grade 11 math twice :(:(

[skychy]

awesome man ur a great teacher!

[iiL0V3chibi]

Sal is funny along the death part :)) =))

[Seattle206723]

Food (Sal) = Math Videos

Math Videos (ME) = A's in intermediate Algebra

Me ( Sal (Food) ) = ME ( Math Vidoes) = A's on intermediate Algebra

Got it thanks :)

[morganthem]

Sal(thanks) ≈ more smarties

[onlyoneskiez]

Thanks! GET A's ON TEST XD

[richy70blitz]

One of the most unique and clear explanations of a function..AMAZING!

[encrypto123]

GIVE SAL MORE FOOD!

for more VIDEOS!

thumbs up SAL. i wish you'd take up teaching as a profession.

[OuttaEgypt]

That Sal(food) analogy is going straight to my index card notes. Easier than pie!

[BCstoodios]

what happens when you put drugs into Sal?

[ixest]

@BCstoodios You ( Sal ( Drug ) = High Sal ) = Jail

[BCstoodios]

my names brad

[tomstar1800]

i still dont get it...

[Blahhumbugify]

I think I'm in love with you.

Please stay on youtube forever.

[omgitskher]

ily sal!

[asohisidore]

Great sense of humor

[asohisidore]

you make t easy to understand.

[asohisidore]

True dat, u r funny. I wish all the math teachers in the world were funny like you.

[josenros]

me(Khan Academy) = happy

[npsz9769]

Thank you.

[MrKiromunist]

The sal(food) function may seem ridiculous, but in mainstream microeconomics (neoclassical), that's really what we do. The firm is a function, you put "stuff" into the firm and it produce things... like a firm(input) function :)

[ohhhliviaful]

Thank you so much! You have no idea how much this helped.

[gur0004]

I Finally get this concept. looks intimidating but thanks to Sal i finally get it lol.

[12cyberspy12]

no dude u didn't confuse us, in fact you made it much more easier.

[tjwhonder2010]

My name is Tim. Thanks Sal

[RADIOACTIVEBUNY]

Oh, and what if I put math videos into your food?

[RADIOACTIVEBUNY]

will make videos for food.

[MsTriara]

You're the best math teacher ever!!