选项
A.
A.$frac{1}{3(x+1)}+frac{x-2}{3(x^2-x+1)}+C$
B.
B.$frac{1}{3(x+1)}-frac{x-2}{3(x^2-x+1)}+C$
C.
C.$frac{1}{3}ln|x+1|+frac{1}{6}ln(x^2-x+1)+frac{1}{sqrt{3}}arctanfrac{2x-1}{sqrt{3}}+C$
D.
D.$frac{1}{3}ln|x+1|-frac{1}{6}ln(x^2-x+1)+frac{1}{sqrt{3}}arctanfrac{2x-1}{sqrt{3}}+C$
正确答案：D