Infinite sum of infinite negative series e^(-nt)

In summary, the sum of e^(-nt) as n approaches infinity is 1/(1-e^-t), which can be found using the formula for an infinite geometric series with the common ratio of e^-t and the first term of 1. This formula can also be simplified to 1/(1-e^-t) when a=1.
  • #1
thomas49th
655
0
Find the sum of
e^(-nt) as n = 0,1,2,3,...

Apparently it's 1/(1-e^-t)

Can't use normal geometric series formula though as if a =1, r = e?
Any ideas
Thanks :)
 
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  • #2
thomas49th said:
Find the sum of
e^(-nt) as n = 0,1,2,3,...

Apparently it's 1/(1-e^-t)

Can't use normal geometric series formula though as if a =1, r = e?
Any ideas
Thanks :)

As long as t>0, you can treat this as the sum of an infinite geometric series.

The common ratio is e^(-t), which has magnitude less than 1. First term is e^0 = 1.

The sum is a/(1-r) = 1/(1-e^(-t)).
 
  • #3
of course when the condition of a=1 occurs it's just 1/(1-r). it was very easy then. doh :)
 

1. What is the formula for calculating the infinite sum of infinite negative series e^(-nt)?

The formula for calculating the infinite sum of infinite negative series e^(-nt) is:

Σ e^(-nt) = 1/(1-e^(-t))

This formula is also known as the geometric series formula.

2. What is the significance of the infinite sum of infinite negative series e^(-nt)?

The infinite sum of infinite negative series e^(-nt) has many applications in mathematics, physics, and engineering. It is used to calculate the total energy of a system in quantum mechanics, to model the decay of radioactive materials, and to solve differential equations, among other things.

3. Can the infinite sum of infinite negative series e^(-nt) converge to a finite value?

Yes, the infinite sum of infinite negative series e^(-nt) can converge to a finite value under certain conditions. This occurs when the absolute value of the ratio between consecutive terms (r) is less than 1, meaning that the series is convergent. When r is greater than or equal to 1, the series is divergent and does not have a finite sum.

4. What is the relationship between the infinite sum of infinite negative series e^(-nt) and the exponential function?

The infinite sum of infinite negative series e^(-nt) is closely related to the exponential function. In fact, when r is less than 1, the infinite sum of infinite negative series can be rewritten as 1/(1-r), which is the same as the power series representation of the exponential function. This shows that the infinite sum of infinite negative series converges to the exponential function under certain conditions.

5. Are there any real-world applications of the infinite sum of infinite negative series e^(-nt)?

Yes, there are many real-world applications of the infinite sum of infinite negative series e^(-nt). One example is in finance, where it is used to calculate the present value of a stream of future cash flows. It is also used in computer science to approximate infinite series, and in chemistry and biology to model chemical reactions and biological processes, respectively.

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