Maclaurin Series for ln(1+x^2)/x

9mmv2
Messages
1
Reaction score
0

Homework Statement



Find the Maclaurin series for : [ln(1+x^2)]/x

Homework Equations



f(x) = \sum f^{n}(0)/n! * x^{n}

f(x) = f(0) + f'(0)(x) + f''(0)(x)^2/2! + ...

The Attempt at a Solution



I got stuck right away, as how do I determine f(0) when you can't divide by 0? Similarly, for f'(0), f''(0)?
 
Physics news on Phys.org
Find the Maclaurin series for [ln(1+x^2)]/x by
Finding the Maclaurin series for ln(1+x^2)
then the Maclaurin series for [ln(1+x^2)]/x is
(the Maclaurin series for [ln(1+x^2)])/x
 
Method 1: Find the Maclaurin series for ln(1+x^2), then divide that by x.

Method 2: Use the fact that limx→0 f(x) = 0, so set f(0) = 0.
If you need to justify this, define g(x) such that g(0) = 0, g(x) = f(x) for all non-zero x. Clearly, g(x) and f(x) have the same Maclaurin series.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top