Introduction to parametrizing a surface with two parameters | Multivariable Calculus | Khan Academy

[@khanacademy]

@Frinniz you're right. Sorry about that.

[@ゾカリクゾ]

how did the response comment get down here? Let's help it :=D

[@benjamin.burton]

This was posted before comments where nested. There was no "REPLY" button back then.

[@abhiaerospace]

finally... the world has a math teacher.

[@Shamap37]

13 years, still appreciating the hard work Sal puts in his videos, and especially his drawing skills

[@jrdnwilkin]

Thanks for helping with my last minute finals studying. Also I believe it should be (3pi/2) on both the S and T axis at about 9:40 rather than (3pi/4)

[@ZzSlumberzZ]

i'd like to stop for a moment and appreciate how good the hand drawn illustrations are.

[@ngalawena]

I think it should be 3pi/2, not 3pi/4 on your graph. :D

[@AmeerulIslam]

yeah.. that's why I just moved to the comment section to see what others think..

[@inox1ck]

I didn't notice. It was at 3 quarters so 3/4*2π=3π/2, he forgot that 2.

[@oneinabillion654]

Yea that's right

[@shuyuanwang1197]

exactly！

[@gardeniabeauty16]

You're really a great professor. Sometimes the videos are long, but every time i finish one I always understand the concept so much better! (I'm a conceptual person, I have to learn the concept before doing the math. You are GREAT at explaining concepts.) :]

[@comprehensiveboy]

Well, that was neat as heck.

[@xMeshuggahx]

I found this video very interesting but I can't find the sequel to it. Has it just not been uploaded yet? Thank you

[@maximocaceres4685]

Incredibly useful, thanks again sal!

[@sumitgupta6905]

This one reminded me of Grant's (3 blue1brown) topology video in which he maps pairs of ordered points on a loop onto a surface and then onto a torus. Loving this course.

[@julijangrajfoner1730]

To visualise easier, check out this video at 5:34

[@prub4146]

Where can I find the full playlist for the old version?

[@vinaykumar-dp8ej]

thank you sir for visulazing the graph !!! and for easy explnation

[@Clammychow]

Bro you are actually a god thank you hope you are doing well 12 years later 💀

[@abinashmandal6202]

please make videos on differential geometry like fundamental forms of surface

[@filomenamendes5349]

I can't find words for how thankful I am. 🙏🙏

[@droher1344]

thats the best looking hand drawn doughnut i've ever seen

[@arneoosterlinck7590]

Thanks for the great visualisation!

[@EntwinedGraces]

mathematical recipe for making doughnuts :D

[@משהלוי-ה4ר]

thank you very much!

[@eminentjonfrost]

I saw doushnut before doughnut xD but thank you Khan

[@drhf1214]

I understand it more! thank you!

[@Daedrex]

You lost me at green donut

[@dhimanroy1671]

Would you please tell me that in which university you take classe and give this illustrious lectures?

[@BicycleFunk]

Starting to comprehend. Thank you.

[@dashiellv]

Why put extra arrows on the axes in opposite directions? Doesn't an arrow mean that there is an increase in that direction?

[@johngonsalves5268]

Surely you are joking Mr. Khan! 270 degrees = 3 pi/2 in leu of stated 3 pi/4 Thanks for all the great insights. I'm very grateful for your help on my budget :0)

[@rizvanahmedrafsan]

people make mistakes, man :)

[@SteamPunkLV]

I'm 3 years late, but don't use big words if you don't know how to use them :p

[@patty5800]

I always thought that it just meant it continues on to infinity, like when we first learned about lines you put an arrow on both ends

[@zuwir]

Excelent video. Excelent class.

[@jeffgalef121]

What's the difference between a parameter and a variable?

[@andrewvictor1489]

I think the same , the three variables can specify any point in a space but two variable can specify any surface in a space and 1 variable can specify any curve in a space

[@Frinniz]

I just want to point out that you say 3pi/4 a few times in this video, when you mean 3pi/2. Otherwise, you're doing a great job.

[@Sarah-zi3bw]

Samuel Khan, you make a mistake, it should be labeled 3pi/2 , not 3pi/4 on the axis at 9 minutes and 40 seconds into the video.

[@Mankind5490]

lol its salman khan

[@monjuls]

also the areas shaded are not matching with top view figure.

[@Waranle]

Thank you Sal

[@rrravi203]

nice explanation sir

[@nipunhi]

Is the angle s, the angle between the x-z plane or the x-y plane?

[@dogeteam2235]

this is very late but s is the angle between the radius line (in the video denoted a) and the x-y plane

[@emilianotca]

Great explanation, but it is 3*pi/2, not 3*pi/4 :)

[@AjayPatel-te4kb]

Amazing sir

[@TheBlo6]

Great video. Thank you!

[@pljehyun]

yay, i love yeti doughnuts! thanks sal!

[@drover7476]

Cool video

[@rodrigo_t9]

Why isnt b considered also a parameter?

[@_HowHardCanItBe_]

to bad patrick didnt make a video about this...

[@reik2006]

really good explained sal ;)

[@MisterBinx]

Yeah I caught taht 3pi/4. I bet he was think of 3/4 of one revolution. Good to know even this guy makes mistakes.

[@ゾカリクゾ]

bad to know... we are less perfect than we want to :(

[@bosung90]

at 18:10 you are shading the wrong part!

[@obogz]

I like pie 8-}

[@MisterTutor2010]

Homer Simpson: mmmm Torus :)

[@-InsanelySick-]

you say zy axis all the time, dont you mean the zy plane?

[@mitsosgamatos5598]

Khan I love you for your lessons they are awesome! But please, please, PLEASE fix the 3pi over 4. It's 3pi over 2 and I've seen it in another video too and it pisses me off, I don't know why, but it does! FIX IT!

[@tks9367]

It really bothered me that he didn't close the left-hand side of his donut all the way....

[@queenstrategy904]

I can learn anything: including how to fail this class

[@hafizmasum9600]

Best

[@torstein99]

you know it as "donut"

[@devin9544]

Is it not 3pi/2 and 3pi/4? That was annoying me the whole time.

[@BubbaOrtiz3]

What the he11 is a doughnut?

[@moomoorawrrawr]

may i borrow your brain?

[@ゾカリクゾ]

T H A T I S C R E E P Y

[@caelawnn]

doushnut

[@chempoint5854]

:D

[@chempoint5854]

:x