Power Series Calculator

Want to determine the infinite series problems of a specific variable? Try the power series calculator to get the exact solution for free.

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Table of Contents:

Introduction to Power Series Calculator:

Power series Calculator with steps is an online source that helps you to evaluate the infinite series problems of a specific variable. It is used to find power series representation of the radius of convergence and interval of convergence in a fraction of a second.

Power Series Calculator with Steps

The power series representation calculator is a learning tool that helps you to learn the concept of power series function easily without any difficulty because it provides you solutions in step by step method quickly and easily.

What is the Power Series?

Power series is defined as the sum of all the infinite series polynomials of one variable in an infinite number of terms. It provides an interval in the form of the radius of convergence that may converge or diverge when the interval is less than or greater than the real number R.

The process power series is an important method in calculus for solving differential equations and complex functions for high-order terms.

Power Series Formula:

Power series formula is the sum of all the infinite series for all real values x. The power series formula used by the power series calculator is,

$$ \sum_{n=1}^{\infty} a_n (x - x_0)^n \;=\; a_0 + a_1 (x - x_0) + a_2(x - x_0)^2 + … + a_n(x - x_0)^n + … $$

$$ |x - c| > R\; \; \; 0 ≤ |x - c| < R $$

  • Σ is the symbol of the sum of all polynomial
  • x0 is the initial value
  • a0,a1,a2,..... is the coefficients of polynomial
  • Series is bounded between the Interval 0<|x-c|< ∞
  • For convergence, the series solution must be |x-c|< R
  • Series diverge when the solution is |x-c|>R

How to Calculate Power Series?

To find a power series representation for the function, the power series solver uses the infinite series test that enables you to get the solution in the form of convergence or divergence of series. Here is the stepwise calculation of the power series problem.

Step 1:

Identify the given function and the radius of convergence.

Step 2:

After identification, applies some tests like the ratio test, and the cauchy test to find whether the given series converges or diverges.

Step 3:

After applying the test, if the solution is x > r then the series diverges or if the solution is in the form of r < x then it converges. If solution r = 0 then your particular test is fail, you can apply another test so that you donot get the zero solution.

Step 4:

For the interval of convergence, you can use the radius of convergence of series result to get the interval convergence solution of power series under the given condition.

$$ 0 ≤ |x - c| < R $$

Solved Example of Power Series:

Let's observe an example of a power series along with its solution which was obtained from a power series calculator with steps so that you can easily understand its conceptual theory.

Example:

An example of a power series to determine the given series has a radius of convergence and interval of convergence.

$$ \sum_{n=1}^{\infty}(n + 1)!(x + 3)^n $$

Solution:

As you can see the x = -3 is the series of convergence. For the value of x, it applies a ratio test

$$ L \;=\; \lim_{n \to \infty} \biggr| \frac{a_{n + 1}}{a_n} \biggr| $$

$$ =\; \lim_{n \to \infty} \biggr| \frac{(n + 2)! (x + 3)^{n + 1}}{(n + 1)! (x + 3)^n} \biggr| $$

$$ =\; |x + 3| \lim_{n \to \infty} (n + 1) \;=\; \infty $$

As you x≠ -3, so series converges x = 3. The radius of convergence is zero R = 0 and the interval of convergence is x = -3.

Example:

Determine the convergence or interval divergence of a given series,

$$ \sum_{n=0}^{\infty} \frac{x^n}{n!} $$

Solution:

$$ ρ \;=\; \lim_{n \to \infty} \left[ \frac{\frac{x^{n + 1}}{n + 1)!}}{\frac{x^n}{n!}} \right] $$

$$ =\; \lim_{n \to \infty} \left[ \frac{x^{n + 1}}{(n + 1)!} . \frac{n!}{x^n} \right] $$

$$ =\; \lim_{n \to \infty} \left[ \frac{x^{n + 1}}{(n + 1)!} . \frac{n!}{x^n} \right] $$

$$ =\; \lim_{n \to \infty} \left[ \frac{x}{n + 1} \right] $$

$$ =\; |x| \lim_{n \to \infty} \frac{1}{n + 1} $$

$$ 0 < 1 $$

How to Use the Power Series Calculator?

The power series representation calculator has a user-friendly interface so that you can use it to calculate the infinite sum of polynomials in less than a minute.

Before adding the input value in the power series solver, you must follow some simple steps so that you do not face trouble during the calculation process. These steps are:

  1. Enter the power series function in the input box.
  2. Enter the order of series from 0 to n in its respective input box.
  3. Select the interval of the power series from the given list.
  4. Review your series input value before hitting the calculate button to start the calculation process.
  5. Click the “Calculate” button to get the desired result of your given power series.
  6. If you want to try out our power series expansion calculator first then you can use the load example to get more clarity about its working principle.
  7. Click on the “Recalculate” button to get a new page for solving more convergence of power series problems.

Outcome of Power Series Representation Calculator:

Power series calculator with steps gives you the solution to a given series of polynomials problem when you add the input to it. It provides you with solutions in a step-wise process in no time. It may contain as:

  • Result option gives you a solution for infinite series polynomial problems.
  • Possible step of the power series convergence calculator provides you solution with all the calculation steps of the polynomial of infinite order problem.
  • Plot option provides you solution in the form of a graph that sketches using the values from the given.

Advantages of Power Series Solver:

The power series representation of a function calculator will give you tons of advantages whenever you use it to calculate infinite series problems. These advantages are:

  • Our power series to function calculator saves your time and effort from doing lengthy calculations of the infinite series problem.
  • You do not need to make any external effort just add the input value and all calculation processes are done in the calculator automatically.
  • The power series finder is a free-of-cost tool so you can use it to find the solution of a polynomial equation of infinite order.
  • It is a versatile tool that allows you to solve various types of polynomial power series equations to find whether it is converge or diverge.
  • You can use the power series convergence calculator for practice so that you get a strong hold on this concept.
  • The power series expansion calculator is a reliable tool that provides you with accurate solutions every time whenever you use it to find a power series representation for the function.
  • Power series calculator with steps calculate power series with a complete process in a step-by-step method so that you get a better understanding.
Related References
Frequently Ask Questions

How to find radius of convergence of a power series

To find the radius of convergence of the power series let's suppose an example with the solution to understand the process. For example, for the radius of convergence for the series $$ \sum_{n=1}^{\infty} \frac{x^n}{x2^n} $$

Solution:

Apply the ratio test on the given function,

$$ R \;=\; \lim_{n \to \infty} \biggr|\frac{a_n}{a_n+1} \biggr| \;=\; \lim_{n \to \infty} \biggr| \frac{\frac{1}{n2^n}}{\frac{1}{(n+1)^{2n+1}}} \biggr| \;=\; \lim_{n \to \infty} \frac{(n+1)2^{n+1}}{xn^n} $$

Simplify the given expression to the radius of convergence R for the given power series,

$$ \lim_{n \to \infty} \frac{(n+1)2^{n+1}}{n2^n} \;=\; \lim_{n \to \infty} \frac{n+1}{2n} \;=\; \frac{1}{2} $$

What is the coefficient of x^3 in the power series

To find the coefficient of x3 in a power series ∑_n=0 an(x−c)n, you need to determine a_3, which represents the coefficient of x3.

  1. Identify the general term of power series ∑_n=0 an(x − c)n for x3 specifically corresponds to a_3 (x - c)3.
  1. Expand the coefficient: $$ x^3 - 3cx^2 + 3c^2 x - c^3 $$

To find a_3, match the expanded series to the general form, and the coefficient of x3. For example, let’s say you have a specific power series Σ_n=1 a_n xn. To find the coefficient of x3. The coefficient a_3 is the coefficient of x3 in the series Σ_n=1 a_n xn.

What is the power series approximation for log 1/x

To find the power series approximation for log⁡(1/x), let's take the Taylor series expansion of log (1 + y) around y = 0.

$$ log (1 + y) \;=\; y - \frac{y^2}{2} + \frac{y^3}{3} - \frac{y^4}{4} + … $$

Put y = -x in the above expression,

$$ log(\frac{1}{x}) \;=\; log(1 - x) $$

The series becomes after adding y = -x

$$ log(\frac{1}{x}) \;=\; -x - \frac{(-x)^2}{2} + \frac{(-x)^3}{3} - \frac{(-x)^4}{4} + … $$

Simplify the above expression such as,

$$ -x \;=\; -x $$

$$ \frac{(-x)^2}{2} \;=\; \frac{x^2}{2} $$

$$ \frac{(-x)^3}{3} \;=\; - \frac{x^3}{3} $$

$$ \frac{(-x)^4}{4} \;=\; \frac{x^4}{4} $$

The power series approximation value is,

$$ log(\frac{1}{x}) \;=\; -x + \frac{x^2}{2} - \frac{x^3}{3} + \frac{x^4}{4} - … $$

What is the difference between a power and geometric series

The main differences between a power series and a geometric series are present in their definitions, forms, and the types of terms which is,

Geometric Series: A geometric series is a specific type of series where each term is a constant multiple of the other term. It has the form ∑_n = 0 arn, where a is the first term (constant) and r is the common ratio.

Power Series: A power series is a more general type of series that involves terms of the form a_nx, where a_n are constants and x is a variable. It has the form ∑n = 0 a_nx.

Both series involve sums of terms, a geometric series focuses on multiplying each term by a constant ratio to generate subsequent terms, while a power series involves terms where coefficients can vary and are typically multiplied by powers of a variable x.

Additionally, their convergence criteria and representations differ significantly due to their respective forms and definitions.

What is the interval of convergence of a power series

The interval of convergence of a power series ∑n=0 an (x−c)n is the set of values of x for which you find whether the series converges or diverges. First, you find the radius of convergence then apply the rule of finding the interval of convergence in power series

  • For convergence, the series solution must be |x-c| < R.
  • To diverge the solution must follow the condition |x-c| > R.

$$ (c - R,\; c + R) $$

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