Limit of Taylor Polynomial for Tn(x) as n Approaches Infinity

Kqwert
Messages
160
Reaction score
3
Member warned that some effort must be shown.

Homework Statement


Let Tn(x)=1+2x+3x^2+...+nx^(n-1)

Find the value of the limit lim n->infinity Tn(1/8).

The Attempt at a Solution


How do I solve this? I know how to write the polynomial as a series, but not sure how if this is the best way of finding the limit.
 
Physics news on Phys.org
Kqwert said:

Homework Statement


Let Tn(x)=1+2x+3x^2+...+nx^(n-1)

Find the value of the limit lim n->infinity Tn(1/8).

The Attempt at a Solution


How do I solve this? I know how to write the polynomial as a series, but not sure how if this is the best way of finding the limit.

You need to make your best effort and show us how far you can get.
 
I solved it now - thanks.
 
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