Compound Interest and e (part 3)

[Thornshadow17432]

Press 9 over and over again for beatboxing.

[deltasworder1x]

All of my questions involve find the interest. No one goes over that!

[orange1872003]

I have noticed that people seem to continuously comment about this particular subject not being covered in school. Being that I received my early education from a public school, I can understand the confusion and concern surrounding this question.

I think a more appropriate approach to the question would by WHY is this topic not covered, or covered in great detail, in public schools.

Could it be......the economy, as we know it, probably wouldn't exist if students were properly educated

[Acerola211]

Small thing - Should be 100r% instead of 10r%.

I love these videos! I'm a cellular and molecular biology major watching these for fun, I'm sure these will be extremely useful once I enter the work force and will have to finance myself.

[caswellmiles]

Mr. Kahn please excuse but address my confusion:

I'm confused by the statement that x = r /n or that X= annual interest rate/periods per year. This would mean that X is 5%.

You just defined X as the PAYMENT in one period X= P(1+r/n) = $50*(1.05) = $52.50.

How does x as $52.50, a specific number equal x as 5%, a relative number?

[ProjectD13X]

love these videos, so helpful in every subject you teach

[parklinkin52]

Sal don't those people reciting e and pi just memorise the digits rather than tapping into some kind of universal memory as you seem to be suggesting?

Of course, anyone who can recite 22514 digits is a freak, but it just shows their amazing powers of numeracy and memory right?

[parklinkin52]

Sal many of the comments here are true: textbooks and schools are useless at teaching this stuff, so how did you get so damn good at it?

[vickiormindyb]

My friend can see all those numbers AND add them up in his head. He freaked out the cashier at the grocery store when he added it up as fast as the computer did.

[Cherivier]

i think there is a minor error in the video. 3:17, it'd be 100r%

[vickiormindyb]

You lost me w/ the term 'e.'

My financially proficient friend is asleep, and I'm not EVEN going to wake him up to ask him. I have no idea how he'd respond to a phone call after one in the morning to ask him an economics or mathematical question.

What is e in mathematical terms? Or are you talking about Excel?

[herrgrillparzer]

@vickiormindyb think he's talking about euler's number (;

[ProjectD13X]

@vickiormindyb e is a number, if you graph out y=(1+1/x)^x it will have an asymptote of 2.71so on and so fourth and a scientific calculator hit 2nd LN and youll get e

[matthewzoot]

mate u are an awesome teacher!

[Flows234]

Daniel Tammet was able to recite pi to around the 22,000th place.

[kingjoker54]

LOL " Start a new cult". You made me crack up thanks for being a great teacher.

[ToujoursLAmour]

Hahaha "If you're in the mood for starting a new cult, perhaps." Excellent dead-pan delivery. I agree with you about the imaginary numbers; surely they hold some secrets about the universe.

[MsTerriwest]

thanks for explaining this :) makes sense now !! unlike my stupid textbook..

[redthunder3979]

too bad they do not teach this in school

let me say that again

too bad people don't learn this in school

[Trangalanga]

school doesnt teach it the same way that sal does

[redthunder3979]

anyone who works too hard and no money should watch this 2X

the bank is steeling your money ......

[CH4NNELZERO]

Don't you mean 100r ? (time 2:40)

[visbygp]

Yep, just a technical mistake.

[tom123ek]

don't use arrows instead of "="

[MyOverflow]

These magical numbers ARE related.

e^(i*pi) = -1

Also, search "the answer to life, the universe, and everything" into Google, it = 42 :P

[FreezingSun14]

@MyOverflow you forgot one ;) e^(pi*i)=-1, but the most famous and in my opinion more awesome and beautifull formula is euler's identity, which is

e^(pi*i)+1=0

this not only includes e, pi, and i, but also includes 1 and 0, obviously important numbers in mathematics.

[eoghanmartin]

funny & intresting

[ZuberHKS]

Google is also calculator. You can type e.g. 6*6 and then shows up an outcome. 36 :)

[CogitoErgoCogitoSum]

Yes, thanks for that. Sal said those very words in this video. Did you not watch it?

[CogitoErgoCogitoSum]

Did you know that the limit of the compound interest equation (continuous compounding)... actually approaches e ?

[rohan123444]

sorry, one more thing i know its not equal but how can you use Pe^r instead of the other formula?

[rohan123444]

could somebody explain this to me?

P(1+r/n)^(nt)=Pe^r

im so confused on this

is it equal because when you substitute it doesnt give you the same answer

COULD SOMEONE PLEASE EXPLAIN THIS

[alphaferrari]

cult...?hahahahahaha.......!

[vkgoku2012]

Hey man I really need to know more about E and ln.

[jokumusic]

LOL @ starting an e cult and financing it.