# [solved] Define x-range for Series expantion

GROUPS:
 Hi all,I am pretty new (i.e. 2 days old) with Mathematica and so far enjoy the power of it.My question is how-to make a series expantion for a certain x-range of the function.The problem is that my function has quite some curves and I want to series expand in a local minimum of the function to know the curvature of this local minimum.Imagine a Sin series and you only want to series expand in a local minimum - this is exactly the same problem.I assume I can expand another function which is defined only in an interval around the local minimum of the orignal function ? But isnt there a nice solution to this problem ? Best!PS: The assumption argument would be nice to use but this is not the same as defining a range.
3 years ago
8 Replies
 If possible, can you give an example of the kind of series expansion you are looking for from an example function?Please take a look at the Series function if you have not already.
3 years ago
 The function I have is the one in this figure. This function needs to be series expanded at a=-0.15 m. BUT the range of the series expantion is important. I only want to series expand between -0.18 and -0.12, to get the exact curvature of the (almost)  ~x^2 well. I had a look in the Series function description already but there is no such thing as boundaries on a series expantion. I assume it is possible though ? Otherwise my strategy would be to define a new function only defined in this interval and then series expand this but this sounds like a detour. You got a better ideas, Sean ?
3 years ago
 Sean Clarke 1 Vote I'm not sure I understand what you mean by boundaries in this case. It sounds like you want to use the Series function and only apply it over a certain range of values.A better question to ask is, how would you go about doing what you want by hand for a simple example?
3 years ago
 Taylor Expansions are defined at a point, not over a range. the higher the order of the polynomial, the wider the range it will fit...