How to differentiate power series starting from 2 for e^x?

In summary, a power series is an infinite series of the form ∑(n=0 to ∞) an(x - c)^n, used in mathematics to represent functions as an infinite sum. To differentiate a power series, term-by-term differentiation can be used. The radius of convergence of a power series is the distance from the center of the series to the point where it converges, and it can be determined using the ratio test or the root test. A power series can only converge within its radius of convergence and may converge or diverge at its endpoints depending on the values of x. In Taylor series, a power series is used to approximate functions by representing them as an infinite sum of their derivatives evaluated at a specific point.
  • #1
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Homework Statement


for d/dx(e^x) , the series should be start from 2 rather than 1 , right ? because when k = 1 , the circled part would become 0 , the series for (e^x) is 1 + x + ...

Homework Equations

The Attempt at a Solution

 

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  • #2
The circled part is correct. There, the index of the sum notation is just shifted up by one, therefore the indices appearing in the term must be shifted down by one. If you compute the series terms by terms you should find that it's indeed the power expansion of ##e^x##.
 

FAQ: How to differentiate power series starting from 2 for e^x?

1. What is a power series?

A power series is an infinite series of the form ∑(n=0 to ∞) an(x - c)^n, where an is a sequence of coefficients and c is a constant. It is a type of infinite series used in mathematics to represent functions as an infinite sum.

2. How do you differentiate a power series?

To differentiate a power series, we can use term-by-term differentiation. This means that we differentiate each term in the series separately, using the rules of differentiation. The resulting series will be the derivative of the original power series.

3. What is the radius of convergence of a power series?

The radius of convergence of a power series is the distance from the center of the series (c) to the point where the series converges. It is denoted by R and can be determined using the ratio test or the root test.

4. Can a power series converge at its endpoints?

No, a power series can only converge within its radius of convergence. At the endpoints, the series may converge or diverge depending on the specific values of x.

5. How is a power series used in Taylor series?

A Taylor series is a type of power series that represents a function as an infinite sum of its derivatives evaluated at a specific point. It is used to approximate functions and evaluate their values at specific points. Power series can also be used to find the coefficients of a Taylor series.

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