Understanding the Maclaurin Series for Trigonometric Functions

In summary, the conversation discusses the Maclaurin series for f(x)=cos x and how it can be used to approximate a function at 0 and become increasingly accurate with more terms added. The conversation also mentions that the Maclaurin series for cosine is equal to cosine when an infinite number of terms are added, making it a useful tool for evaluating integrals. The conversation ends with a question about how to write the series in the long form, with a clarification that it is done in terms of a Taylor series centered at a=0 with an infinite number of terms.
  • #1
nicolette2413
8
0
The question is Find the Macluarian Series for f(x)= cos x. Not a hard problem. What I'm having an issue with is Maclaurian series over all. I don't really understand them and how to use them. Our textbook discussion on it is not very helpful either. Can anyone point me in the right direction for help here?
 
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  • #2
What do you mean by "use them"? Can you give an example of the kind of thing you feel you do not understand?
 
  • #3
A Maclaurin series is the same as a Taylor series centered about 0. (a = 0, in other words). This means locally, at 0 the series will approximate a function the best, then it becomes a little off if you move away from 0, however this can be fixed by adding more terms to the series.

Basically the practice behind cosine is is that if we add an "infinite" number of terms the Maclaurin series for cosine actually equals cosine. This becomes a very nifty tool for evaluaing some integrals.
 
  • #4
Ok, that makes sense. So to write the series out in the long form for cosine you start at x=0 and work up from there? (such as to 1, 2, or 3) or do you work up in another manner such as in degrees or in terms of "x" such as x2, x3?
 
  • #5
You work in terms of a Taylor series with an infinite number of terms, with all of the terms of the infinite series centered about a=0.
 

FAQ: Understanding the Maclaurin Series for Trigonometric Functions

What is a Maclaurian series?

A Maclaurian series is a representation of a mathematical function as an infinite sum of terms, using the derivatives of the function at a single point as coefficients.

What is the purpose of using a Maclaurian series?

The purpose of using a Maclaurian series is to approximate a function by using a finite number of terms, which can make calculations and analysis easier and more efficient.

What are some common issues with Maclaurian series?

Some common issues with Maclaurian series include convergence issues, where the series may not converge to the actual value of the function, and accuracy issues, where using a finite number of terms may result in a less accurate approximation of the function.

How can convergence issues be addressed in Maclaurian series?

Convergence issues in Maclaurian series can be addressed by checking the radius of convergence, which is the distance from the center point where the series converges. If the radius of convergence is too small, the series may not accurately represent the function and alternative methods may need to be used.

What steps can be taken to improve the accuracy of a Maclaurian series?

To improve the accuracy of a Maclaurian series, one can increase the number of terms used in the series or use alternative methods such as using a different center point or using a different type of series, such as a Taylor series.

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