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
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(1+1/m)m
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1
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2
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10
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2.59
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100
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2.70
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1000
|
2.716
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10000
|
2.718
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“e”
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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
The Solution is:
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. |
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,
So, the balance after 3 years is approximately $2,568.06.
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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!
ReplyDeletetess,
ReplyDeletei 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