Parametric equations 2 | Parametric equations and polar coordinates | Precalculus | Khan Academy

[@kennethsilvestre4296]

thanks, your skill is better than my professor. now I understand this topic. , thanks a lot

[@danielscott7187]

9:00 "What the shi-" Khan got mad! :-O

[@ultimate01]

Daniel Scott he was saying shape

[@ketofitforlife2917]

@@ultimate01 😞

[@darkdudironaji]

In my school this is usually where single variable calc ends, but none of the professors ever get here. So my multi variable calc prof is going over it quickly. Even though he obviously knows what he's talking about, he isn't very good at teachin. So, I am very grateful for these vidjas

[@ivanfrohlich]

I can't believe that I am using youtube in the third semester in uni

[@CaptainHeadcrab]

I'm using this because the textbook my professor required us to get is so convoluted, it's impossible to read it and learn anything meaningful.

[@bluewolfer]

Great guide, been slacking in class and this is really helpful!

[@bychen5011]

It's been 9 years. How has ur life changed?

[@mrbubblewand]

Thank you for this video. I ended up getting an awful instructor for this term and this video gave a much more meaningful and contextual explanation for parametric equations.

[@hatman4818]

6:40 was what I needed, and the second you said substitute t for x, it made sense.

[@derrick7436]

It has to do with distribution of exponents. Think of it as multiplying the expression by itself, or (x/5-2)(x/5-2) which allows you to FOIL it out and that's where you get x^2/25 - 2x/5 - 2x/5 + 4 And that simplifies to to what you see in the video. You've probably figured that out at this point. But I also was initially caught off guard by that as well and I'm sure I won't be the last.

[@MustNotRead]

Sal is my personal Math mentor / guru who's (or is that "whose"?! argh!) videos i consult to make things clear. thank you Sal!

[@bychen5011]

It's been 11 years. How has your life changed?

[@dapiridoob]

@carolinagringa khan is everyone's math teacher. Praise khan. all hail lord KHAAAAN

[@IvyANguyen]

Stewart book or my prof or this? I would take THIS by far!

[@qualquan]

Good. Specially showing advantage of parametric over non parametric functions

[@user-ig1em7wd9c]

thank Allah , i understood

[@DehXable]

Khan is your math teacher.

[@zack_120]

Convincingly argued why parametric is required in some circumstances

[@mitchwulfman]

I'm in the same position, this guy is great.

[@envoyizclutch1227]

How did you get the 4/5 x when you were simplifying the equation?

[@dynamo-db]

-2/5 x plus -2/5 x (because the terms in the parenthesis are squared and that is how it distributes, or FOILs out if you learned that).

[@MusicNerd999]

You're my hero.

[@zain4019]

MusicNerd999 your profile pic XD

[@Jem93rocks]

Thank goodness for Khan.

[@buckeylaslo5121]

I don't know if you still need this, but that is call factoring a binomial. This particular property is called the difference of squares. Just type "Factoring a binomial" into Google and you should find what you're looking for.

[@Mollehertz]

You, my good sir, is awesome. !

[@ucrclxl]

@menamedon92 in this case x(t) indicates initial position of object (10) and direction (+) and speed (5) per unit of time (t). So if you basically change +5t into -5t the "car" starts moving backwards.

[@WoWDart]

Grad students should not be allowed to teach college courses. Just because they are a grad doesn't make them good at teaching. I'm sick of TAs too. The whole system is broken. We are so lucky to have you Sal.

[@ketofitforlife2917]

This was absolutely excellent. My uni prof described this like some sort of quantum physics. Wasting money on the school. Smh

[@InSingularity]

You, sir, are awesome.

[@mephatboi]

the sad truth is, most "teachers" either lack the insight/knowledge or r not considerate enough to explain ideas/concepts like sal does

[@deathalert]

You are currently saving my good marks in Math 1010. This is my studying for my final :P

[@thetgwarrior]

Thanks so much!

[@josef959]

P (2ap, ap^2)

[@bf2gamestotal]

congrats man

[@tehbrookzorz]

At 6:43, where can I find a video or explanation on how to apply an exponent to a fraction of x such that I get this result? It has been too long since high school.

[@aubreydavid]

Sal. You're so thorough with this number thing, brah. You must be an engineer or something...Right?

[@themushroom2130]

he is

[@ProdigiousAsian]

i love you for this

[@breakdancer100]

I can't believe I'm actually using youtube to study for my finals.

[@bychen5011]

It's been 8 years. How has ur life changed?

[@alotan2acs]

amazing stuff

[@gobberpooper]

@aubreydavid I think he's an economist. He was on CNN explaining the credit crisis and has am MBA and such and such

[@djstrobe1234]

Couldn't you substitute the time in for X if you have the simpler version of the perimetric equations

[@GarageGamere]

It would be cool if he added explosions to the last drawing. (Just for laughs.)

[@TuscaniManiac]

nice !

[@bychen5011]

What has changed in your life in the last 11 years since this comment was written?

[@IsaacC20]

Ok, now's lets account for the Einstein's law of relativity lol.

[@ntskl]

Oh wow. Sqrt[10] really is 3 point something something.

[@williamwarren9397]

this is pre calc?? i never heard of them til linear algebra in uni

[@ureasonnable]

how can t= sqrt of 3? shouldn't it be instead sqrt of 10 which is rounded to 3.17 ?

[@bioart9780]

May I ask what type of teaching software is this?? i wanna give a lecture on certain topic using this technique.... anyone can help??

[@NathanPlaysGames1234]

www.quora.com/What-software-does-Khan-Academy-use-to-record-their-lectures Found this, hope it helps

[@DrQlimakz]

okay thats the same as me here in europe :)

[@COYADD]

Are parametric equations not infinite? My calculator seems to think that whatever number you multiply by t is the amount of t values you're allowed. I basically get a big middle finger from my calculator everytime I want to use parametric equations.

[@abhinaydubey3432]

9.3 exercise n.c.e.r.t. book

[@DrQlimakz]

what level math is this equivalent to in the US?

[@jaredchannel3270]

Qlimakz pre calculus

[@drevil37373]

for this why use a parametric function when you could y as a function of x.

[@mellowmorgan]

So... Calculus 3 is off to a REALLY bad start :/

[@kevinjosecheng823]

They might as well get rid of math teachers and have a stock of your videos and play them in class instead. Saves money, and students actually learn. I just solved our education problem.

[@DoctorShrooms12]

Calc 2 is frustrating...

[@STRYKER1467]

thats too much for me my brain is gonna die soon ...

[@haniyaafsar2545]

Sir no clear explanation