Who else was thinking when the phone rang, "Better call Sal"?
@user-qp1jh5vm8m
4 жыл бұрын
Please somebody redesign the tablet to be able to function with improvement multitasking hardware?love math math indeed.1/501=
@curryrice9577
8 жыл бұрын
I love you. This is the best form of charity (that helps me). Thank you
@roketboyd
15 жыл бұрын
wow. u are so easy to listen to. amazing. Really. Everything u say gets sunk into my mind. So simple, so genius. Thanks much Sir.
@KurdstanPlanetarium
10 жыл бұрын
A very good problem in exponential growth. Thank you
@Dnizzle7
12 жыл бұрын
@MrAimsworth Well, if you're learning about expo growth, most people use the equation A=Pe^rt in which e^rt is the exact same as e^kt. Both equations are the same, just with different variables. P is the initial amount, e is the natural log to the power of (r times t). r is the rate and t is the time. I hope I answered your question!
@Incrue
9 жыл бұрын
Hi Sal, I think you maybe should re-do this one, and start of by introducing the general formula for exponential growth y=a*b^t, (where b is the growth factor, a is the initial value) and then move on to how it's useful to manipulate this into an exponential function with base e. I was a bit confused by this at first, and I see others in the comment section are too. (2)
@sanjanasoni2262
5 жыл бұрын
isn't it geometrical progression?
@drevil37373
11 жыл бұрын
makes more sense to use b(t)= I(2())^(t/r) where r is the amount of time it takes to grow or double in size. you could also switch the two to whatever the rate is like in this equation it is 420/100 per hour. so 100(4.2)^(t/1 hour)
@indiajag1
12 жыл бұрын
You are AWESOME. I am starting to like Calculus because of you. Thank you!!!!!!!!
@ericjamesharlow
14 жыл бұрын
Thanks man, I had to learn this for biology at UCSD and even the professor couldn't explain it as well as you did.
@oliviakim0221
10 жыл бұрын
Helped a lot. You are the best!!!!
@alkalait
14 жыл бұрын
@ redgenda: "ln^(4.2)=x" translates to "the exponent x on e (e^x) that gives 4.2". so remember, ln^(4.2) is That exponent "x". Put now that Same exponent "x" on e (e^x) and ask yourself what would you get...
@rvngizswt
10 жыл бұрын
What do you do if you end up with a fraction as k? Like it's ln(87.14/101.3)/3000? We can't use calculators.
@gdawgrapper
15 жыл бұрын
I was wondering myself, but he did eventually get there around 10 min. For me, it's like you, a heck of a lot more understandable as b(t) = 100(4.2)^t. And if that wasn't intuitive enough, take the points (0, 100), (1, 420), and (2, 420*4.2) and plot them, then run an exponential regression to find the equation and from there be able to more easily answer all the questions--but that goes into graphing calculator proficiency.
@veeds74123
12 жыл бұрын
thank you sooo much! this helped a lot!
@guitarzilla
16 жыл бұрын
exponential decay? Have you developed a mathematical expression for describing the imminent loss of penicillin?
@ionisator1
5 жыл бұрын
omg i just noticed i can make exponents with ctrl + alt for example 2²
@sanjanasoni2262
5 жыл бұрын
doesn't work in my computer
@nocturnalvisionmusic
2 жыл бұрын
Nice :) can't do that on mobile though :(
@iwantitpaintedblack
7 жыл бұрын
y=a * b^x Final = Initial x Growthrate^time growthrate = x√Final/Initial unknown final = Initial x knowngrowthrate^x
@Elwyndor
9 жыл бұрын
How do you solve a problem like this if you do not know how much bacteria you start with?
@erickjoshuanebreja6154
6 жыл бұрын
Where does the "e" come from? Is it mandatory???
@pvchio
12 жыл бұрын
I have watched some of your videos, but I still don't understand what k actually means. In my textbook, it says that k is the relative growth rate and k is used in the equation A(t) = Ae^kt. I know how to calculate the k. However, if I am asked to find the relative growth rate, I will first divide 420 by 100 and say that the rate exactly equals 4.2 and that is the k. but why I need ln(4.2) = 1.435 = k, it doesn't make sense if the growth rate is 1.435. can you explain their difference, please
@MrAimsworth
13 жыл бұрын
Where did the e^kt come from? Is there a formula for expo growth that i am not aware of?
@TripedalTroductions
9 жыл бұрын
THIS IS THE SAME EXACT QUESTION ON MY HOMEWORK XD... coincidence? I think not!
@Sintaxx2
9 жыл бұрын
Calculus Early Transcendentals, 7th edition, Exercise 3.8.3? :p
@TripedalTroductions
9 жыл бұрын
yes! XP
@nocturnalvisionmusic
2 жыл бұрын
That's neat :D
@alexanderpaterson3123
15 жыл бұрын
AGh You scared me. I forgot This window was open when it started playing.
@mintismile
14 жыл бұрын
luvv ur vids!! i think i understand more from here than from my actual teacher sometimes [haha phone from dish network :P]
@brco2003
16 жыл бұрын
b(t)=100(4.2)^t Wouldn't this be a simpler form of the expression for the number of bacteria after t hours?
@ricksterp34
13 жыл бұрын
thanks!
@afreakenracoon
14 жыл бұрын
HELP!!! a car was bought for 25000$, each year it depreciates by 15%... a) write an exponential formula that demostrates the cars value in (n) amount of years after it was purchased/ b) what is the cars value at the end of 3 years c) after how many years will the value of the car be half of the original price? PLZ HELP!!!! THANK YOU!!!
@crodd63
14 жыл бұрын
the way you do it in the states is alittle different than that of nova scotia
@megami.x
14 жыл бұрын
thank you, it helped a lot
@dianadai1411
11 жыл бұрын
do you have any specific answer?
@willdrougas
15 жыл бұрын
great video i learned alot
@Kruemo
12 жыл бұрын
It's the Euler Number (For natural growth). It's an infinite number just like Pi, look it up on wikipedia ;).
@MustafaHammood
11 жыл бұрын
Thanks Sal
@ny1fanta
14 жыл бұрын
you dont hav to use product rule when you mutilply 100e^ln....?
@Xenthoid
13 жыл бұрын
This is the exact same problem ( problem 3) i was looking at in my book, Early Transcendentals
@EliteRainSnipers
10 жыл бұрын
How did you go from e^k=4.2 to K=ln(4.2)
@collegetech8936
10 жыл бұрын
When you take the natural log of both sides, the e goes away, leaving the exponent (k) and then the other side is ln(4.2)
@katelynvalles7962
6 жыл бұрын
I think you should redo this problem. It was very messy, pixelated and all over the place. I had to rewind the video because I lost focus.
@bhz10
13 жыл бұрын
there is a subliminal message in the first problem ;D Thanks for the help
@nocturnalvisionmusic
2 жыл бұрын
That's pretty neat ;)
@brco2003
16 жыл бұрын
hahah the phone that was brilliant! ur the best!
@Soulscarz
14 жыл бұрын
this is the exact problem in my book chapter 7.3 #3 lol thank you i needed help on c
@venisefagan8949
Ай бұрын
Whats the name of the book?
@RealSpiderk
11 жыл бұрын
this guy likes the sound of his own voice way too fucking much
@danielfloresresendiz1183
9 жыл бұрын
420??? thats the devils number!? :O.great vid besides that though
@Carlisle412
9 жыл бұрын
There is no place for superstition in mathematics.
@zoebrizwantalkhani1002
8 жыл бұрын
666
@ionisator1
5 жыл бұрын
?? 666 is not 420 lol
@sammurray7219
11 жыл бұрын
"The population has increased to $4.20" haha @15:28
@angelo4chris
14 жыл бұрын
thanx one more time... im taking algebra 2
@RaZoRfIsHiE
12 жыл бұрын
420 and rasta colors, i think he's trying to tell us something...
@MartinLarsson
15 жыл бұрын
Did you watch the whole video?
@tripathilavkush
7 жыл бұрын
Answers (b) 7406, (c) 10591.8, (d) 3.22 hours
@dudeB15
13 жыл бұрын
i dont get it
@thisismycoolnickname
11 жыл бұрын
I think it would be much easier to understand if you used b(t) = ia^t, rather than b(t) = ie^(kt).
@gamobigz
13 жыл бұрын
I think he needs to give a more intuition on how e^ln4.2 works.
@marcellohro
14 жыл бұрын
yes it would
@alkalait
14 жыл бұрын
sorry I didn't notice you got it. anyhow, i got to play smart :P
@Crazyscience101
12 жыл бұрын
use hippo campus .org, they are the same videos without the annoying comments or ads.
@TheMillenniumTigers
11 жыл бұрын
12 people are public school teachers
@mebeast227
11 жыл бұрын
someone buy this guy a calculator
@karamwahba1591
5 жыл бұрын
First of all, what is the proof of this formula?
@pman2010
11 жыл бұрын
And yet here you are listening to it. Someone likes making stupid comments way too much.
@funnytroller4489
8 жыл бұрын
Our school does y= bg^x
@sanjanasoni2262
5 жыл бұрын
same, it's also called geometrical progression
@brycehazen
11 жыл бұрын
420
@njeridiva85
10 жыл бұрын
skipped steps and messy hard to follow
@Badboyjoshyyy
7 жыл бұрын
omg this is the exact same problem in my book that i came to look at this video for
@RealSpiderk
11 жыл бұрын
haha, you must have a high tolerance for people wasting your time then
@FreeeeWillie
10 жыл бұрын
lol
@FreeeeWillie
10 жыл бұрын
please buy a calculator
@MrHellokitty2828
12 жыл бұрын
terrible hand writing software
@Phagocytosis
11 жыл бұрын
I don't agree at all... I don't think you have a good idea of what this person is like.
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