English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

2006-12-08 01:44:05 · 3 answers · asked by Anonymous in Science & Mathematics Mathematics

3 answers

use substitution
u=ln(r+1)
du = 1/(r+1) dr
so
integral of [ln(r+1)]^2 / (r+1 ) dr = integral of u^2 du = u^3 /3 + C
= (ln(r+1))^3 /3 +C .

2006-12-08 01:46:54 · answer #1 · answered by Anonymous · 1 0

∫[ln(r+1)]² / r+1 dr =

u = ln(r+1)
du = 1/(r+1) dr

=>
∫[ln(r+1)]^2 / r+1 dr =∫u² dr
∫[ln(r+1)]^2 / r+1 dr = (1/3) u³ + c

∫[ln(r+1)]^2 / r+1 dr = (1/3)*[ln(r+1)]³ + c

2006-12-08 03:47:46 · answer #2 · answered by Luiz S 7 · 0 0

put ln(r+1)=t
1/r+1=dt
t^2dt on integration gives t^3/3+C
reverting back tothe original variable
=[ln(r+1)]^3/3+C

2006-12-08 01:47:32 · answer #3 · answered by raj 7 · 0 0

fedest.com, questions and answers