Domain of a function

[alexandea93]

its a line not a semi colon

[DemonikOu]

3:00 That can be also written as {x∈R*}!

R* means all R except 0 ;)

[PortugalFootballer]

I LOVE YOU, you are saving me for my diploma exam this week.

[IceRingCrazy]

The very last 4 minutes confused me. Make another video to explain them please.

[lifeofcows]

@shanglawt look for a pattern. If the denominator is higher than 1 or lower than -1, the end result is always lower. If not, then the end result will increase. Example: 1/0.5 = 2, 1/0.25 = 4, etc.. If that's true, than what is 0? Surely can't be infinity, because 1/0.infintesimal = infinity. So a denominator of 0 is undefined.

[zodiac832]

Thank You for the video!! i looked at it before i went to take my final, really helped me out

[shanglawt]

Isn't 1/0 is 0?

[Leonie9220]

@shanglawt hahahahaha if you give 1 euro for no one, what gonna happen?................ You still have your 1 euro!

[ShonieShanya]

@shanglawt If you type that in your calc you should get "ERROR". However 0/1 is 0. :)

[RemoteHelper]

Thanks! :-)

[gopaulnarin]

I dont know what it is .........ITS UNDEFINED lol

[Rensyl]

My "Math II" Proff sucks.

Ur the math dude!!

[444zane3]

@Rensyl math 2? you mean like algebra 2 or something?

[Rensyl]

@444zane3 I'm from Argentina and im studying economics.

We have MAthematics 1, 2, 3 and 4.

We don´t call it calculus, algebra or etc etc.

Greetings.

[rafay19593]

ahhhh something happened to my pen! ... Lol!

[IRAQYsniper95]

my teacher fucking sucks at teaching ur the fucking best man. fuck my math teacher.

[brownje552]

I wish you were my teacher you make it seem so easy than my teacher...

[sunjanium]

i have a d in algerbra 2 because i dont understand the way my teacher teaches me so now i am going to try and watch ur videos for functions to try and salvage my grade wish me luck friends

[Smitherines161]

@sunjanium yeah, this dude is awesome! im only in algebra 1 but i had a test and i had no idea what to do because i didnt understand how my teacher taught it either so i searched ''how to do ....'' and i totally understand now!

[cooleeohs]

I love you

thank you :)

[vladikuss1]

I would like to know what program you use for you video. (not for video recording but for blackboard)

[TheCreepyKrippy]

Natural numbers are from 1 and more, which means the second example you can also say Domain= { x Belongs to N }

[Hello99825]

Very informative, thank you for the video.

[17mikicar]

The real question is: " Is poison in the domain of a function called Sal?" :))

[BuVaN0]

How do you know to set the square root function to greater than or equal to zero and not less than or equal to or less than or greater than? And how would I find a domain regarding a polynomial: x^2-5x+6?

Thanks

[ooCONROYoo]

I'm confused: For the third example, how could x be greater than or equal to 3? If x is equal to 3 then the product is the square root of 0, which is undefined (as far as I know). Should the domain not be x is greater than 3?? Could someone please explain this to me, thanks.

[paul7048]

@ooCONROYoo This is a different example. Because the example says square root of x-3, we can't have any value less than 3. I can put in 3, and get the square root of zero which is acceptable, but I can't but 2, because you can't take the square of a negative number. If the example was 1/square root of x-3, then you would set it as x-3>0. Why? Because remember 0 cannot equal the denominator.

[mnbvcxz995]

93,807 students have teachers that should be fired.

[TheAllboutwin]

Does anyone know where I can find a video that shows how to use calculus to find the range of a function?

[TheAllboutwin]

<3<3<3<3<3<3<3<3

[jenbuku]

*gets distracted by tv.* oh no! "rewind"

[phillipishot13]

dang why can't YOU be my teacher(: you teach me wayyyy more than him lol

[phillipishot13]

dang why can't YOU be my teacher(:

[Oneto5]

THANK YOU SO MUCH! You teach me more than my teacher!

[mitchel1023]

should've hit the books. basic responsibility

[Saronaist]

Now i can write my calculus exam without any problem. This sexy voice has made life easier for me. Am so happy :)

[HelloxImxMichelle]

YESSS. after 7:30 life just started making sense <3

[jninlove]

NICE JOB!! THANK YOU

[rccaulfield]

i fully understood all math vids up to this point then all of a sudden this is gibberish to me? Where is this absolute value coming from, whats the square root of a negative number all about?

[EilteHunterDKRogue]

@rccaulfield yeah same here!!!

[mitchel1023]

@rccaulfield shouldve watched the previous lessons. basic algebra

[rccaulfield]

@mitchel1023 should have read my comment properly. Basic reading.

[dracsweety]

Piecewise???

[wolswoys]

A new registar company mydomainshop. net fast, easy, cheap

[fuhq2010]

Thank you.

[NekroNiki13]

you are my god now thank you helping me with everything i was totally conuffsed with.

[780wolfx2]

Hi Sal, can you do a presentation on piecewise functions?

i was never taught them in highschool and apparently i need to know them for my calculus class.

as always, you're the best!

[1523119]

Oh Sal. You are the best! Thank you. God bless you man!

[IThekingofkings100]

Thanks

[kwazy349]

Thanks for the help!

[C3P0meetsData]

Sal has the sexiest voice ever.

[1523119]

@C3P0meetsData He totally does, I go to sleep while listening to him and learning Math. Ahhhh Sal. Who knew?

[SpoiledLogic]

@C3P0meetsData He does, he does.

[Sinshana]

@C3P0meetsData Yes, he has the most seductive voice. In one of his videos he almost cut off the video cause his wife came home which almost broke my heart, but in the end he chose to teach me math instead of attending to her first, LOL.

[josuanette]

thank you so much sir . I am overwhelmed with your response. Now I know that zero is allowed but not n/0. I would like to be honest. This video helped me so much !!!

[josuanette]

Sir i am confused with the first example f(x)=x^2. What if you will solve for f(0) ? that would make it 0^2 which is = to 0 right? then the domain should be {xER ecept 0} is that correct. Pls help me iam confused. Thanks

[helloXX9]

@josuanette f(x) = x^2 Domain {x E (All reals)}

the reason is f(0) = 0^2 = 0

0 is a valid answer, if I were to graph this I would get (0,0) as a point

[agent2993]

Hey sal can you please do a video on inverse functions...plz

[spikeyredcactus]

i dont understand near the end, for the absolute value of x, he says that x can be the same as -3 or less than. So if that is true for example, -4-3 = -7, which is a negetive number. How does this comply with the domain? thanks

[MrCoolguy6273]

i got it till the end :S

[eeTTeeTTeeTT]

because in the question got the modules x , any x in the modules also will become positive value.

[Marco027]

Im sorry wouldnt X<-3 in the absolute value one..be wrong though..becuase.. you cant have any negative inside the square root..?

[mikedensity]

@Marco027 no, because absolute values do not have a negative value.

[sue69696]

thx alot u explain very nicely

u should procceed u will help alot of ppl

[albertbeccu]

Thanks a lot! :-)

[astt171]

Thank you so much for your helpful videos. I do not know how to thank you.

All I can say is that you are amazing.

[fdxnaoseinomes]

Thanks khan you helped me once again!

We learn a lot in your videos, great job you do +5*

[NorwegianNightmare88]

how do you write so good with a mouse on the computer?!?!?!?!?

[IRAQINBK]

he uses a pen tablet

[Mejiera12]

8bit nice one catching that

[limon914]

Very helpful, thanks!

[Archer6633]

If it only was recorded by a camera.. you would rock..!

[mack520]

hey mon- where do we send money? Paypal?

[VFCfuturelove1]

crap I CANT FIND WUT I WANT!!.. so my homework goes a little like this ..Find the range(dependent),R, of every funcion given the domain (independent),D.then here's #9-f(x)=x(cubed)+3 then to the side D={-3,0,3}..HELP?!?!=[..don't get it..i have 2 turn this in 2morrow..will make sure 2 pay attention in class latr..bt for now HELP PLEASE!!=]

[sblackstone]

What I would like to know is why this is the first result when you search for 'funions' on youtube.

[8bit2008]

Forgive me if I'm wrong, but on that last question, isn't the domain the set of all INTEGERS such that x is not equal to 1?

[dotageek11]

can you find domain and range of y=2x^2-x? thanks a lot.

[abedbae]

The last problem was tricky! almost got me :)

[majorkeybaree]

absolute value?

[abedbae]

thanks!

[buzwazfuz]

thank you, you always get me through my math and physics homework. thx agian

[jensennn93]

thank you sooooo much!

[sarafann]

ty, saved my grade :)

[RoseDelion]

I can't stand my math teacher, he didn't teach us this, he just gives us paper, does 1 example. And expects us to get an A+

I need help on how to graph dilations/translations

Thanks your very helpful =)

[DCaple0013]

u have a lot of time to be doing this. thank you tho for real i got this take home quiz and ive been falling behind. good man u r. peace.

[levimariah]

Sal; can you help me understand how to determine if a relation is a function or not, like y=x^2 vs. x=y^2 one is a function and one is not,i'm haveing a hard time deciphering the info. also; could f(x) be considered y when x is in the relation? thanks, Tim

[khanacademy]

for y=x^2, y is a function of x or y=f(x)=x^2 because if you input any x into the f(x)=x^2, you get a unique value. For x=y^2, x is a function of y for the same reason (x=f(y)=y^2) but y is not a function of x. For x=y^2, if x=4, then y could be +2 or -2 so you don't get a unique y.

[payasitopimpim2002]

instructive useful .....awesome...thanks my friend............

[nateums]

i love u....

[WorldCollections]

Beautiful !

[sonycatr]

That cool little E means that x is an element of the real... E for element....

[EnigmaBentony]

This is awesome :D I'm in pre-cal now, and I'm starting to love this kind of weird stuff :P I'll definitely show my math teacher; maybe we'll use one of your vids in class :) Peace, you rock.

[zramdeen]

ty... but dam pen!!!! ahhahahahhaha

[blover22]

ive been looking for this forever!

well like, 2 days. but thanks it was great