∫{（x+1）^2/[x(x^2+1)]}dx=

题目

∫{（x+1）^2/[x(x^2+1)]}dx=
A.ln|x|+x+C B.ln|x|+ln(1+x^2)+C
C.ln|x|+2arctanx+C D.ln|x|+C

答案

∫{（x+1）^2/[x(x^2+1)]}dx
=∫{（x^2+1+2x）/[x(x^2+1)]}dx
=∫1/xdx+∫2/(x^2+1)dx
=.ln|x|+2arctanx+C
选C