Parametric equations 3 | Parametric equations and polar coordinates | Precalculus | Khan Academy

[@fernandopaulino2055]

Khan is life

[@musical17]

this was SOOOOOOO good. i would love school if all my professors taught the way you do! thank you so much

[@mellowmorgan]

My mind tends to wander during lectures, as it does on these videos. But on youtube, I can rewind!

[@hami4141]

Woooooo man I wish my instructor taught it this way. Ive been fighting through his heavy Russian accent and wishy washy techniques for weeks!!! You have taken me from elementary algebra all the way through Calc III without fail! I owe you big time.

[@Wpjgdmtu]

Why do I pay for college?

[@ownalicous1]

Wpjgdmtu I pay to be allowed to take tests lol.

[@ripperoni5338]

beccause that unfortunately gives you a degree that you can use to get a job and this doesn't count even though it should

[@puffer_fish58]

same here lol

[@allanparelle9681]

High school*

[@biggieboomboom]

I've thought this many times. What you're really paying for is the formal recognition of having successfully completed a course. Most jobs/grad schools will want to see college credit/a diploma from an accredited university. Is it worth it? That depends; for a programmer, it's not, as there are much cheaper, better options for learning how to code (and that industry doesn't care about degrees). If you want to go to grad school, it's necessary. I have heard of taking pictures of completed Khan Academy courses and using that in application portfolios. Not sure if that would make up for no college credit in calc I-III...

[@gouravtada]

Wooow That ellipse 😳😳

[@aello465]

Am I the only one who is impressed by how well his ellipse fit on the first try?

[@commentedited232]

All students who watch Khan Academy should pledge to donate to this NON PROFIT when they finish their respective degrees and become employed and financially independent cause we all know this will be the real reason we complete our degrees. I will initiate of this pledge.

[@socereally7104]

+Joe Matia I wouldn't feel too bad actually. I am not the best test taker and the calculus course I had in high school was an Advanced Placement course that rushed through calc1 and calc2 pretty rapidly, and I had six other college prep courses along with that in that same year, so I am glad I went through it again in College because it gave me a good refreshing look on Calculus as a whole. And community college definitely helped lower the big price tag ;) Also, at the time i dont think my brain was ready to wrap my head around the concepts at the time. Also, having a bad teacher didn't help either.

[@smitrib]

Oh yes, Sal, I did enjoy that ;)

[@hjback]

Sal you're a hero

[@qualquan]

Good. 2 ways to write ellipse equation and why the parametric form is more informative. Worth pondering.

[@nedsoc]

as long as the variable remains constant throughout the problem, it does not matter what it is. (For example, you could have been using any letter other than 'x' for all of your variables thus far in math class)

[@cappmasters7253]

🎉😊thank you sir

[@rushanz]

Thanks it helped me clarify what was going on

[@diffusiventity]

Wonderfully explained

[@FirstLast-yz6rw]

Incredibly small correction: at 12:45 to avoid defining the same point twice, bounds for t should be 0

[@zeus433]

Ur method won't be correct bcos it implies "t not-equal-to 2pi"

[@luthfanjulian6563]

dear the one who's behind the sound of Khan Academy Channel, Thank you very much for all of your videos. now i wonder how do you know all the math's insight, could you give me references of the books. i'm a college student from indonesia which i want to learn all the math things in my winter vacation.

[@kangaroo1179]

thank you for helping my homework

[@deathalert]

Aiii luvz khanacademy. Helpt mi wit maii math

[@robutubin]

Informative vid, thumbs up for this guy

[@InSingularity]

I'm learning this in high school right now

[@wasdtomove924]

in a problem like x = 2 sin ^2(t) and y = 3 cos ^2 (t) can you use the trig identity to make it x/2 + x/3 = 1? to make it into an ellipse because i checked the back of my book for the graph and it was a line

[@bdom11]

Thank you so much!

[@AndreCarneiroSantiago]

Does anyone understand that for his math t could moving around clockwise 3/4 of pi, or counter clockwise -1/4 of p? I don’t see how three points solve the problem in this particular case.

[@aimanacap]

do you have videos which have more difficult problem ?? such as x=2cost + cos2t , y=2sint - sin2t

[@dvcv92]

thanks!

[@Visiorex]

"I'm using this blue color a little too much. It's getting monotonous." BLUE CAN NEVER BE MONOTONOUS.

[@woodenjaw]

I love you Sal!

[@Lucaplusleia]

I'm going to always "mildly pat my back" lol :)

[@mohamedatef9688]

I have something more complex and I can't figure it out , x = t^2 + tan t , y = 2t - cot t .... I will appreciate any help , thanks

[@lolzomgz1337]

5:30 What's the difference between an equation and an identity?

[@SebastianLopez-nh1rr]

None

[@SebastianLopez-nh1rr]

+Sebastián López It's just a convention to call the very useful and general equations.

[@illiniballin11]

yes

[@BahaarC3PO]

I need help please. Here is the question: Let P be a point on the curve x(t^2), y=(1/t). If the tangent to the curve at P meets the x- and y-axes at A and B respectively, prove the PA=2PB. I have found the gradient of the tangent at point P (by getting derivatives of x and y) and I have found the equation of the tangent. I have also found points A and B by using the equation of the tangent. I got: A (3(t^2),0) and B (0,(3/2t)). Now, I am stuck. What do I do? Please show the steps! Thank you!!! (my book sucks)

[@S3ANZ13]

though it could get monochromatic...

[@AnonymityIx]

In orbit around something sounds so redundant lol

[@MrVargasesteban]

i feel weird with the ''arc sin'' but great channel

[@themin91]

in 12:12 what did you making of?

[@Cr381v3]

it is amazing how you can be interested by math!

[@steave707]

Dude.. i love you..

[@InSingularity]

7:20 it's a football

[@akvolkswagen]

I hope there teachers were as good as Khan! lol

[@ABH1212]

Isn't sin^2(y)=sin(siny)?

[@hawrahussain4605]

What's an ellipse?

[@darkassassin7741]

Hawra Hussain an oval

[@neverlastingworld]

yea... this was pretty damn helpful! haha

[@Reydriel]

I really hate the sin^2 notation; it doesn't make any sense. 'Sin' is a function, therefore the exponents should act like how it does on other functions (sin^2(x) should mean sin(sin(x))...)

[@irlbrisa7775]

What about x=tcost y=tsint !!!!!!!!!!!!!!!!!!

[@alitou001]

@leoncio91 before they had no youtube but they hadless distractions,now we have youtube but a lot of distractions (facebook,xbox,psp,apple apps.....) .

[@inmotion86]

This is the equation God used to create the egg.

[@leoncio91]

lol i almost feel bad for the people who went through college a few years ago, before youtube, and online help, etc good thing for us though haha

[@loverofbeats]

rad!

[@citrous]

this isnt polar tho what

[@anantnaik12]

@deathalert and your spelling..

[@Cr381v3]

it wasn't me who put a thumb down on your comment... i just think it's amazing. in a good way. you don't have to be so offensive.. :P

[@IanVallone]

takes too long to get to the effing POINT.