Taylor Expansion Without Variables?

In summary, the conversation discusses a basic equation involving constants r' = k - g*r and the need to consider variations from the average values. Suggestions are given to substitute and possibly simplify the equation without using Taylor's series. Clarification is sought on whether the variables are functions or numbers.
  • #1
Poppop
5
0
This is just part of a larger problem, but I have a basic equation r'=k-g*r, where k and a start out as constants, but then I need to treat everything as if it can vary slightly from the average. For this, I set r=r_ave+dr, g=g_ave+dg, and k=k_ave+dk. Now I need to work these into the first equation, so I guess I need to Taylor expand them, but I don't see how to do that with this sort of equation. Any suggestions?
 
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  • #2
Is r' the derivative of r? You say you "need to treat everything as if it can vary slightly from the average", but what do you want do do with it? What problem are you trying to solve? I don't think you need to expand this into a Taylor's series, just substitute:
r'= k_ave+ dk- (g_ave+ dg)(r_ave_+ dr)
Now, are you thinking of dk, dg, and dr as functions of some variable (apparently r is since you are using r' but you didn't say what the variable is) or just numbers? If numbers just go ahead and multiply it out. If dk, dg, and dr are very small, you can ignore products like (dg)(dr) and simplify a bit.
 

1. What is a Taylor Expansion without variables?

A Taylor Expansion without variables is a mathematical method for approximating a function by using a series of polynomials. It is used to expand a function around a specific point, called the center, without the use of any variables.

2. How is a Taylor Expansion without variables different from a regular Taylor Expansion?

In a regular Taylor Expansion, the series of polynomials includes terms with variables. However, in a Taylor Expansion without variables, the series only includes constant terms without any variables. This allows for a simpler and more direct approximation of the function.

3. What is the purpose of using a Taylor Expansion without variables?

A Taylor Expansion without variables is used to approximate a function in situations where the use of variables would be too complex or impractical. It is also useful when dealing with functions that have a large number of variables, making it difficult to expand the function using traditional methods.

4. How is a Taylor Expansion without variables calculated?

To calculate a Taylor Expansion without variables, the function is first evaluated at the center point. Then, the derivatives of the function at that point are calculated and used to create the series of polynomials. Finally, the series is added together to approximate the function.

5. What are the limitations of using a Taylor Expansion without variables?

A Taylor Expansion without variables can only approximate a function within a certain range around the center point. If the function has a singularity or is undefined at the center point, the approximation may not be accurate. Additionally, the accuracy of the approximation decreases as the distance from the center point increases.

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