Integral x/(1-x) via power series?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 1K views
fahraynk
Messages
185
Reaction score
5
Member warned that the homework template is required
So, ∫x/(1-x)... can I solve this as a power series

∫(x*Σ x^n) = ∫(Σ x^(n+1))= (1/(n+2)*Σ x^(n+2))?

Is this correct? I know there is other ways to do it... But should this be correct on a test? This solution is more fun..
 
Physics news on Phys.org
fahraynk said:
So, ∫x/(1-x)... can I solve this as a power series

∫(x*Σ x^n) = ∫(Σ x^(n+1))= (1/(n+2)*Σ x^(n+2))?

Is this correct? I know there is other ways to do it... But should this be correct on a test? This solution is more fun..

More fun than what? More fun than the exact expression? Is a solution of limited applicability (i.e., is correct only for limited values of x) preferable to one that applies to all x ≠ 1?
 
Last edited:
Ray Vickson said:
More fun than what? More fun than the exact expression? Is a solution of limited applicability (i.e., is correct only for limited values of x) preferable to one that applies to all x ≠ 1?
Ha. Good point.