Critical points introduction | AP Calculus AB | Khan Academy

Sal introduces the "critical points" of a function and discusses their relationship with the extremum points of the function. Created by Sal Khan.

AP Calculus AB on Khan Academy: Bill Scott uses Khan Academy to teach AP Calculus at Phillips Academy in Andover, Massachusetts, and heÕs part of the teaching team that helped develop Khan AcademyÕs AP lessons. Phillips Academy was one of the first schools to teach AP nearly 60 years ago.

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[deborahfranza]

Why my professor couldn't explain this concept so concisely is a mystery to my, but thank you for creating Khan Academy. It has carried my math education in community college all the way up from pre-algebra to now Calculus 1. #Ioweyoumylife

[georgeb]

5:43-6:08 - Critical Point - explanation (what, how to find)
where f'(x) = 0 or undefined 
6:55-7:29 - How to find Maximum/Minimum Value #theory
Not explained how to find critical point 

[ScientificVoyage]

An explanation with exceptional clarity.

[TheAmirSheidaei]

I was just thought this in my AP calculus class! Great job!

[thanaa]

Sal this is one of the most incredible videos of yours!!!

[bilgekyran]

I searched all the internet to check that simple question and couldn't find it anywhere. thank you so much

[mikewarrior]

ur voice makes a lot of difference too
great work

[moonshiry]

Very, very, clear and simple to understand

[michaelhoefler]

Shouldn’t f(x0) also be a local maximum?

[muthyalakoushil]

In class I feel maxima and minima is sooo bore but now I feel so interesting that u so much for khan academy 😍😍😍😍😍😍😍😃😃😃😃😃😃😃😃😃

[MelgMike]

2:37 -- "Not lox, that would have to deal with salmon" - I died laughing when he said that lol

[Do-Some-Change]

I'm not gonna lie when this was uploaded, I just had ended my 1st class

[thatoesia]

this is beautifull...well explained sir

[kylenason]

So, can the global max also be considered a local max when there are points on both sides of it on the graph and interval or can it only be considered a global max?

[harnoorkaur]

the global maximum in the graph is also a local maximum

[DacoRoo]

I'm always amazed that there is never a video that explains what I'm stuck on. Everyone recommends your videos, but they never help me.

[ginevrabianco]

Is it fair to say that if the derivative does not exists at a point, then this critical point can be a local min /local max?

[rileyc]

when u learn about salmon in a math video

[MSDhoni-pzwc]

Hello Khan sir! Sir, why can't we choose the lowest values at the end of the interval??

[iMacBoy]

Can a global minimum or maximum be a local mini/maxi in the meantime?