how could i expand something such as arctan'x into a power series. also how would you be able to find the power series for it?(adsbygoogle = window.adsbygoogle || []).push({});

so far i have managed to work out that:

arctan'x = [itex] \frac{1}{1 + x^2} [/itex]

[itex]\frac{1}{1+x^2} = 1 - x^2 + x^4 - x^6 +...+ (- 1)^n x^{2n}[/itex]

how do you work out the radius of convergence though: i know it is : |x|< 1.. but how do you work it out please?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Power series of arctan'x

**Physics Forums | Science Articles, Homework Help, Discussion**