image

image

Friday, April 11, 2014

The Number "e"

Good Morning Class,

I am Professor Rhea and I will be teaching you all a little something about the number "e"

Now you might be wondering how the letter "e" can also be a number...this is possible because of the brilliant mind of Leonard Euler a Swiss mathematician. 

He found this using the following proof "(1+1/m)^m" and what this means is that as "m" reaches ∞ that (1+1/m)^m converges to "e" and when you plug m into the equation, the outcome stays at roughly 2.71

So "e" roughly equals 2.71

Or...

2.7182818284590452353602874713527 (and more ...) if you want to be exact!

Now because (1+1/m)^m approaches "e", any positive base "b" can be written as a power of "e" 
n(1 + 1/n)n
12.00000
22.25000
52.48832
102.59374
1002.70481
1,0002.71692
10,0002.71815
100,0002.71827
 graph of (1+1/n)^n

For example: (b = e^k) 

Because of this an exponential function f(t)=ab^t can be re-written in terms of "e" as f(t) = ae^kt

f(t) = ae^kt is used in Continous Compounding:

Where...
a = initial value
e = 2.71
k = the interest rate
t = the amount of time the interest rate is compounded over


That is it for our lecture today and if you have any questions you can visit me in my office hours or email me!

Have a good day,

Professor Rhea



Source: http://www.mathsisfun.com/numbers/e-eulers-number.html 

2 comments:

  1. Solid lesson plan. Although I had a semi-decent grasp on "e" before, I now have a much better and feel much more confident about it

    ReplyDelete
  2. jalen,

    very nice lesson! one thing that i would have suggested adding is the connection between the compounding continously formula (A= Pe^rt) and the the natural exponential function f(x) = ae^rt.

    otherwise, nice!

    professor little

    ReplyDelete