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Wednesday, April 16, 2014

The number "e" tess


Hi I’m Professor Richards and today I will be teaching you about the number “e”! the start off the number “e” = 2.71 and is between 2<e<3. The reason why “e” is equal to 2.71 was figured out by Leonard Euler proof. For (obituary) M we see the pattern of the expression  (1+1/m)m.
M
(1+1/m)m
 1
2
10
2.59
100
2.70
1000
2.716
10000
2.718
“e”
 for (1+1/m)m as m= (1+1/m)m =e converges to “e”
this is because (1+1/m)m =e any positive base “b” can be written as a power of “e” (ie, ek=b)
·      So any expentical function f(9)=abt can be rewritten in terms of “e” as f(t)=abt=a(ek)t=aekt
·      Now “k” is called the continuous growth rate   
F(t)= aekt is “b” when “k” is the continuous growth rate
·      If b>1 when “k” is positive
·      If 0<b<1 then “k” is negative

An example is


Let ek=2 and b>1
then in ek=in2
K=in2
K2=0.69 K is the positive when b>1

An example
Let ek=1/2 and 0<b<1
Inek=in1/2
K2=in1/2
K2=-0.69
K in negitice 0<b<1

Here is an example from an everyday situation

An amount of $2,340.00 is deposited in a bank paying an annual interest rate of 3.1%, compounded continuously. Find the balance after 3 years.
The Solution is:
Use the continuous compound interest formula, A = Pe rt, with P = 2340, r = 3.1/100 = 0.031, t = 3. Recall that e stands for the Napier's number (base of the natural logarithm) which is approximately 2.7183. However, one does not have to plug this value in the formula, as the calculator has a built-in key for e. Therefore,
Example Solution

So, the balance after 3 years is approximately $2,568.06.

2 comments:

  1. I really enjoyed your lesson on the number 'e'! I thought it was very insightful and especially helped me to understand the concept of using 'e' to determine monetary values. Thank you very much!

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  2. tess,

    i like that you showed an example verifying what happens with the base b. i would have explained what napier's number means instead of just throwing that in there, since it's not common knowledge, but otherwise, nice job.

    professor little

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