Optimization with Calculus 2

[mariahphilmrazem]

<3 

[kwas244]

only problem i have is that 24 inches squared is the area,and the way you drew it out it was 24x24 giving an area of 576 inches squared... at least thats how i see it

[pur33z]

How the hell do you dislike a KHAN video????????

[jsj89football]

Rather than take the second derivative to determine if it's a maximum, why not just plug 3 and 5 into V' for x? You will see that it is positive at 3, and negative at 5. If the equation goes from a positive to a negative at 4, than this would be a maximum on V.

[tttsang777]

"its kinda sad" LOOL...you make calculus fun 

[ProMidgetPunter]

Why cant you be my calculus professor

[dee5u]

Thanks a lot! Saved me from a headache

[kimdavidj2]

U are an awesome teacher

[LoveThemMusic]

woo hoo thanks

[jessung]

"Sometimes when your brain is in calculus mode, algebra 2 gets difficult." Ohhh yeah.

[soccer5706]

go eat dinner lol

[lucasbudega]

this isn't calculus 2, it's calculus 1

[mlewbank]

@lucasbudega it says calculus 2 because it is the second in a series of videos :)

[destroyedtheozone]

You ought to consider being a radio DJ on your off time. You soothing voice demands such intelligence!

[basketballnc]

sal i love you man... your a far better teacher then my fat ass one at school

[54rohan]

OMG thnx a lot, my calc teacher sucks lol

[Todoslosfritos]

..... CHALLENGE ACCEPTED!!!!

[philsnk]

9x^2.

[mulhaircorey]

I would assume you've gone through the same pain as the students you are teaching, but for time conservation purposes maybe doing them ahead of time would be a good idea. But thanks for your work!

[nickrohn93]

@mulhaircorey I would argue it's much more valuable to understand his thought process whilst digesting the info. It creates a deeper understanding in my mind.

[EWninjah]

Thanks to this, I passed my Calculus test :D

[eowdaoc]

YOU GO THROUGH THE SAME PAIN WE DO, I RESPECT YOU SIR

[saltmasin88]

Tq very much..i learned a lot from u 

[xX0FallenAngel0Xx]

My calculus exam is in two days. You are saving my life right now. THANK YOU.

[dhaval712]

1:43 - 1:48, i hear his saying, "This is sex". This sure is sex to my brain. Good Job Sal.

[SeekTheTruth7890]

I think this is a Calculus 1 problem, not Calc 2

[cucumbersrkool]

@SeekTheTruth7890 it's single variable calculus so probs.

[xxDarkGregxx]

What do you use to write this all on?

[xxDarkGregxx]

What do you use for you blackboard?

[kpacdd]

"when your brain's in Calculus mode, sometimes the Algebra II gets hard!" (: haha. so true

[zadavidson]

You draw a swiss cross and say "crux of the problem." Win.

[Absinthus]

Optimization-calculus is so much fun.

[ANonExistentUser]

You're a credit to the field of YouTutors!

[Seedofwinter]

Sal can you please do reimann sums? I know you have but so much time, but I'd really appreciate it.

[legomoviem4ker]

did this same problem in my class today! haha

[barrettski189]

theres is one thing that confuses me now... if x=0, then the volume should be equal to 48 according to the volume expression?! : /

[emandetrevni]

@barrettski189 multiplying anything by 0 gives you 0

[MummyFish1012]

@emandetrevni not infinity!

[klevn]

@barrettski189 V=W*L*H V(x)=(24-2x)*(24-2x)*x even if you forgot to multiply the height through you would not get 48....24*24 doesn't equal 48....ever...you would get V(x)=576*0

[jrobuck81]

@klevn (24-2x)(24-2x) = 576-48x-48x+4x^2 = 576-96x+4x^2

[RedScorpion97]

You are amazing, I have nothing else to say.

[SoCmodder]

You Sir, are my hero.

[acramsay80]

Really appreciate your videos. The struggles you exhibit help us all feel human!

[mariomaruf]

I have never seen an uglier looking 576 in my life before!

[eboutros12345]

dude..........thanks

[eboutros12345]

dude,...... thank you so much

[chickencombo3]

WE ALL LOVE YOU!!!

[killy0urself]

i LOVE your little side comments in your videos; they always make me smile. thank you for these videos! my professor is extremely boring with his lectures, but you make calc fun. you're awesome!

[Linky360]

I LOVE U

[Linky360]

@Linky360 no.wait.....WE LOVE U!!!!!!!!!

[pistolpetepabian]

we need more people like you on this planet...people who arent afraid to show what they're passionate about and care about what they do

[dianelly]

thank for this vido, GOD bless u

[ohlalaxobeer]

hey how old are you are you a professor? or a student you seem smart

[vivian333999]

i should have memorized my times tables up to 25... hahah. u r a genius

[OARHEGOS]

Bless you, calculus is hard, but listening to you is fun. Thanks.

[TigerXC26]

8:49 to 8:53 LOL!!! i go thru da pain like u do hahahaha!! a calculator would help u know..

[righteousgroove]

The great Sal does not need a calculator :P

[misscollegiate08]

@daseiner it is x = 4

[daseiner]

@misscollegiate08 You're absolutely right. Bad day, sorry for any confusion.

[misscollegiate08]

@daseiner lol thats alright :)

[hockeymo]

like one time during calculus class, i forgot 2x3.

[imadElghourani]

its six bro...

[sharron2792]

you are my hero!

[x5pyd3rx]

Dont feel bad about messing up the basic arithmetic. one time during a calculus exam i literlly forgot how to do long divison =/

[ketchupxsuicide]

you're so helpful =]

[seen8]

so the volume is 1024 inches cubed

[Shitblizzards]

come teach at mcgill! :p

[riku0228]

Couldn't x be equal to (+)(-) 8 at 9:30?

[BloodGL14]

You're using x to represent a length, so the initial interval you're dealing with should be something like [0,12] because you can't have a negative length, which means it should never be negative, but i don't see where the 8 is coming from. But, the idea is that you should watch the initial interval you can work with in the problem.

[aznjwong23]

no. if it was +/- 8 it would be x^2 -64

[DrPeppable]

@riku0228 no, they have to multiply to 48, 8*8 = 64

[shaneymane]

Wow, optimization made easy. Come teach at the U of Arizona.

[superman22x]

Right? lol, I'm a tech student watching youtube to do my learning, lmfao.

[sprinkleOFkawaii]

UCLA too hehe..

[DrPeppable]

@shaneymane or RPI please =)

[marcusjhung]

haha thats like for me too. Calculus mode = Sudden amnesia in basic arithmatic

[BboyKundei503]

I groove on the cyber blackboard. Great work, thanks for sharing.

[johngoforth77]

don't be so hard on yourself Hal, your a badass.... and no careless mistake is gonna change that

[MonaRocks09]

@johngoforth77 his name is Sal

[ahhatheJoker]

@johngoforth77 his name is Sal

[13tubedude13]

you are saving my life :)

[sbrian28]

the flaw of most teachers is that they fail their students by taking the concrete to the abstract, this guy is so effective because he uses abstract ideas for intuition and then brings it down to the concrete with specific examples, you have helped me greatly and i cannot thank you enough.

[vohne]

my god, very good. very very good.

[iluvjiyongx3]

thank u so much for the great visuals! ^^

[Bartisim0]

Thank you for letting me intuitively visualize these universal math concepts!!!

[elementknight]

I appreciate what you are doing here. Thank you.

[colombiantom]

thanks a lot and about the algebra it's okay dude we all make mistakes..thanks to silly mistakes i get the procedure right but not the answer..lol..anyway thanks a lot again

[its123baby]

It's nice to see that even geniuses such as yourself are mortal and struggle through things sometimes as we do :) Thank you so much Sal.

You are helping more people than many teachers help in a lifetime of teaching!

[Waranle]

brco stop being sarcastic you dumb idiot!

[brco2003]

I didn't mean to be rude, I just thought that it doesn't make sense to use advance technology such as this cyber-blackboard and opt to not use a calculator.

Sal, your a big help. Thanks!

[FARecords]

Cyber blackboard? It's Paint..lol

[AkashP4]

Thank you! You are a big help!!